diff --git a/CHANGELOG.md b/CHANGELOG.md
index 868b09b..2f4ca31 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,8 +4,13 @@ All notable changes to this project are documented here. The format follows [Kee
 
 ## [Unreleased]
 
+### Breaking changes
+
+- Warning and error codes drop the underscore after the prefix: `MSKITVER006`, `MSKITPKG015`, and so on, with the same family and number. `NoWarn`, `WarningsAsErrors`, `WarningsNotAsErrors` and `MSKit_SkipPackageChecks` entries that name a code the old way no longer match: rename them. Each section of the [code reference](./docs/reference/codes.md) names the code's former spelling.
+
 ### Added
 
+- Every warning and error links to its section of the [code reference](./docs/reference/codes.md) (`HelpLink`, shown by the terminal logger and IDEs). `MSKit_CodesHelpBaseUrl` points the links at another copy of the page.
 - `manager/`: the first build of `mskit-manager`, the `DragoAnt.MSBuildKit.Manager` .NET tool (`net8.0`, `net10.0`, `RollForward=Major`) that will install, update and migrate the kit. This build has one command, `status [--json]`, which prints the tool version; the logo goes to stderr, only on a terminal and never with `--no-logo`, so `--json` output always parses. Each run writes a log under `<system temp>/mskit-manager/logs/`, named after the command, newest 20 kept. Not published yet.
 
 ### Changed
@@ -14,7 +19,7 @@ All notable changes to this project are documented here. The format follows [Kee
 
 ### Fixed
 
-- A JPEG `PackageIconPath` no longer fails `dotnet pack` with NU5046: the icon is packed as `icon.<extension>`, lowercased (`icon.jpg`), and the nuspec names that file. `MSKIT_PKG015` accepts a 128×128 JPEG as well as a PNG, as nuget.org does ([#11](https://github.com/DragoAnt/MSBuildKit/pull/11)).
+- A JPEG `PackageIconPath` no longer fails `dotnet pack` with NU5046: the icon is packed as `icon.<extension>`, lowercased (`icon.jpg`), and the nuspec names that file. `MSKITPKG015` accepts a 128×128 JPEG as well as a PNG, as nuget.org does ([#11](https://github.com/DragoAnt/MSBuildKit/pull/11)).
 
 ## [0.2.1] - 2026-10-05
 
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 762d448..51e5470 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -19,7 +19,7 @@ You need the .NET 10 SDK and the .NET 8 runtime, plus `sh` (Git Bash on Windows)
 sh tests/run.sh
 ```
 
-It installs the working-tree kit into the sample and the fixtures with `update.sh`, then checks the computed versions for local, branch, pull-request and tag builds, runs the sample's tests with coverage, inspects the packed nuspec, asserts that every `MSKIT_PKG` check fires on the fixtures, and runs `sh tools/docs-check.sh`. CI runs the same script on Linux and Windows.
+It installs the working-tree kit into the sample and the fixtures with `update.sh`, then checks the computed versions for local, branch, pull-request and tag builds, runs the sample's tests with coverage, inspects the packed nuspec, asserts that every `MSKITPKG` check fires on the fixtures, and runs `sh tools/docs-check.sh`. CI runs the same script on Linux and Windows.
 
 The tool's tests run from `manager/`, so its `global.json` selects Microsoft.Testing.Platform:
 
@@ -32,7 +32,7 @@ CI's `manager` job also packs the tool, installs it into a tool path and runs `m
 ## Changing the kit
 
 - A new property defaults with `Condition="'$(Name)'==''"`, so a consumer's value always wins, and gets a row in [docs/reference/properties.md](./docs/reference/properties.md) plus a mention on its topic page.
-- A new check gets an `MSKIT_<AREA><nnn>` code (a shipped code is never renumbered or reused), a message that says how to fix it, a section in [docs/reference/codes.md](./docs/reference/codes.md) headed by the code id without the underscore, a fixture that triggers it and a line in `tests/run.sh`.
+- A new check gets an `MSKIT<AREA><nnn>` code with no separator (a shipped code is never renumbered or reused), a `HelpLink="$(MSKit_CodesHelpBaseUrl)#<code, lower case>"`, a message that says how to fix it, a section in [docs/reference/codes.md](./docs/reference/codes.md) headed by the code, a fixture that triggers it and a line in `tests/run.sh`.
 - `sh tools/docs-check.sh` fails on a property, item or code without its reference entry, on a name the docs mention that the kit lacks, and on a broken relative link; `--list properties|items|codes` prints the kit's inventory with the file and line of each.
 - The README stays short: key features, install, links. Detail goes to the topic page in `docs/`.
 - A new part needs a line in `kit/.toolkit/kit.parts` and its `init.props` / `init.targets` imports in the entry points.
diff --git a/README.md b/README.md
index 686c0b5..15fc5a1 100644
--- a/README.md
+++ b/README.md
@@ -8,7 +8,7 @@ Shared MSBuild settings for .NET repositories that publish NuGet packages: nuget
 
 ## Key features
 
-- **Packages that pass nuget.org's rules by default.** Licence, icon, README, [Source Link](https://learn.microsoft.com/dotnet/standard/library-guidance/sourcelink), symbols, repository and release-notes links, [package validation](https://learn.microsoft.com/dotnet/fundamentals/apicompat/package-validation/overview) and [NuGet audit](https://learn.microsoft.com/nuget/concepts/auditing-packages); nineteen `MSKIT_PKG` checks run on `dotnet pack`, warnings on your machine and errors on CI. [Packaging](./docs/packaging.md)
+- **Packages that pass nuget.org's rules by default.** Licence, icon, README, [Source Link](https://learn.microsoft.com/dotnet/standard/library-guidance/sourcelink), symbols, repository and release-notes links, [package validation](https://learn.microsoft.com/dotnet/fundamentals/apicompat/package-validation/overview) and [NuGet audit](https://learn.microsoft.com/nuget/concepts/auditing-packages); nineteen `MSKITPKG` checks run on `dotnet pack`, warnings on your machine and errors on CI. [Packaging](./docs/packaging.md)
 - **One README for the repository and its packages.** `MSKit_PackageReadmeFrom=README.md` generates each package's readme on pack, with links pinned to the commit. [Package readme](./docs/package-readme.md)
 - **Versions from release tags.** Tag `v1.4.0` and the packages are `1.4.0`; branch builds are `1.4.0-ci.<run>`, pull requests `1.4.0-pr.<n>.<run>`, local builds `9999.0.0`. [Versioning](./docs/versioning.md)
 - **Tests on Microsoft.Testing.Platform v2.** Projects named `*.Tests` become [xUnit v3](https://xunit.net/docs/getting-started/v3/microsoft-testing-platform) test projects with coverage, TRX and JUnit reports, an assertion library and [NSubstitute](https://nsubstitute.github.io/). [Testing](./docs/testing.md)
diff --git a/docs/README.md b/docs/README.md
index 9068739..b3055a7 100644
--- a/docs/README.md
+++ b/docs/README.md
@@ -11,7 +11,7 @@ Read in this order; each page stands on its own, so jump to the one you need.
 | 5 | [Versioning](./versioning.md) | control how package versions are computed |
 | 6 | [Local files and secrets](./local-files.md) | keep secrets and machine-only source files out of the repository |
 | 7 | [Optional parts](./optional-parts.md) | debug a dependency from source, list a project's packages, run Entity Framework migrations |
-| 8 | [Packaging](./packaging.md) | understand the nuget.org defaults and the `MSKIT_PKG` checks |
+| 8 | [Packaging](./packaging.md) | understand the nuget.org defaults and the `MSKITPKG` checks |
 | 9 | [Package readme](./package-readme.md) | generate every package's readme from the repository README |
 | 10 | [Testing](./testing.md) | set up test projects, assertions, mocking and coverage |
 | 11 | [Roslyn components](./roslyn.md) | build analyzers, code fixes and source generators |
diff --git a/docs/build.md b/docs/build.md
index 9956b9a..b5ffa0a 100644
--- a/docs/build.md
+++ b/docs/build.md
@@ -24,7 +24,7 @@ The owner layer adds `IsPackable=True`, `TreatWarningsAsErrors=True`, `NoWarn` `
 | | Developer machine | CI |
 | --- | --- | --- |
 | Version | `9999.0.0` | from the tag, pull request or run ([Versioning](./versioning.md)) |
-| `MSKIT_PKG` checks | warnings | errors ([Packaging](./packaging.md)) |
+| `MSKITPKG` checks | warnings | errors ([Packaging](./packaging.md)) |
 | [`ContinuousIntegrationBuild`](https://learn.microsoft.com/dotnet/core/project-sdk/msbuild-props#continuousintegrationbuild) | unset (PDBs keep real paths) | `true` |
 | Local secrets | created from templates | deleted ([Local files](./local-files.md)) |
 | `TreatWarningsAsErrors` drift check | on | off: CI passes its own `-p:TreatWarningsAsErrors` |
@@ -52,9 +52,9 @@ Declare `TargetFramework` or `TargetFrameworks` once, in `Directory.Build.props`
 
 | Code | When |
 | --- | --- |
-| [`MSKIT_SHARED006`](./reference/codes.md#mskitshared006), [`MSKIT_SHARED007`](./reference/codes.md#mskitshared007) | error: the csproj repeats the shared `TargetFramework` / `TargetFrameworks` value |
-| [`MSKIT_SHARED008`](./reference/codes.md#mskitshared008), [`MSKIT_SHARED009`](./reference/codes.md#mskitshared009) | warning: the csproj sets a different value of the same shape; `MSKit_SkipAudit_TargetFrameworkOverride=True` accepts it |
-| [`MSKIT_SHARED010`](./reference/codes.md#mskitshared010) | error: the csproj declares both shapes |
+| [`MSKITSHARED006`](./reference/codes.md#mskitshared006), [`MSKITSHARED007`](./reference/codes.md#mskitshared007) | error: the csproj repeats the shared `TargetFramework` / `TargetFrameworks` value |
+| [`MSKITSHARED008`](./reference/codes.md#mskitshared008), [`MSKITSHARED009`](./reference/codes.md#mskitshared009) | warning: the csproj sets a different value of the same shape; `MSKit_SkipAudit_TargetFrameworkOverride=True` accepts it |
+| [`MSKITSHARED010`](./reference/codes.md#mskitshared010) | error: the csproj declares both shapes |
 
 `MSKit_GuardXmlPeekRoutine=False` and `MSKit_GuardXmlPeekAudit=False` turn off a cheap text pre-check and always parse the csproj; leave them alone unless a declaration is missed.
 
@@ -86,7 +86,7 @@ A project with `ExcludeFromCodeCoverage=true` gets the [`[ExcludeFromCodeCoverag
 
 ## Central package versions
 
-The parts that add package references also provide their versions: as `PackageVersion` items with [central package management](https://learn.microsoft.com/nuget/consume-packages/central-package-management), else on the `PackageReference` itself when it has no version. Each version is a property you can override, `MSKit_PackageVersion_<Package>` (lists: [Testing](./testing.md#package-versions), [Roslyn](./roslyn.md#package-versions)); `MSKit_ImplicitPackageVersions=False` turns them all off. A `PackageVersion` of yours for the same id fails restore with [`MSKIT_DUP001`](./reference/codes.md#mskitdup001) (bypass: `MSKit_SkipAudit_ImplicitPackageDuplicates=True`).
+The parts that add package references also provide their versions: as `PackageVersion` items with [central package management](https://learn.microsoft.com/nuget/consume-packages/central-package-management), else on the `PackageReference` itself when it has no version. Each version is a property you can override, `MSKit_PackageVersion_<Package>` (lists: [Testing](./testing.md#package-versions), [Roslyn](./roslyn.md#package-versions)); `MSKit_ImplicitPackageVersions=False` turns them all off. A `PackageVersion` of yours for the same id fails restore with [`MSKITDUP001`](./reference/codes.md#mskitdup001) (bypass: `MSKit_SkipAudit_ImplicitPackageDuplicates=True`).
 
 `PrivateAssets=all` is set on references to `Fody`, `ConfigureAwait.Fody`, `IgnoresAccessChecksToGenerator`, `Grpc.Tools`, `Microsoft.EntityFrameworkCore.Design` and `Microsoft.EntityFrameworkCore.Tools`, so these build-time tools never become package dependencies. Add your own `Update` items in `Directory.Packages.Metadata.targets`.
 
@@ -101,13 +101,13 @@ The parts that add package references also provide their versions: as `PackageVe
 </ItemGroup>
 ```
 
-A reference to a `Type="Error"` package fails with [`MSKIT_RES001`](./reference/codes.md#mskitres001), a `Type="Warning"` one warns with [`MSKIT_RES002`](./reference/codes.md#mskitres002). `SkipGlobalRestriction="True"` on one `PackageReference` allows it (an error becomes a warning). The owner layer bans `Moq`.
+A reference to a `Type="Error"` package fails with [`MSKITRES001`](./reference/codes.md#mskitres001), a `Type="Warning"` one warns with [`MSKITRES002`](./reference/codes.md#mskitres002). `SkipGlobalRestriction="True"` on one `PackageReference` allows it (an error becomes a warning). The owner layer bans `Moq`.
 
-**Allow-list mode.** With `MSKit_RestrictProjectReferences=True` (or `MSKit_RestrictPackageReferences`, or `MSKit_RestrictReferences` for both) every reference must carry `Allowed="True"`, else [`MSKIT_RES003`](./reference/codes.md#mskitres003) / [`MSKIT_RES004`](./reference/codes.md#mskitres004). Off by default.
+**Allow-list mode.** With `MSKit_RestrictProjectReferences=True` (or `MSKit_RestrictPackageReferences`, or `MSKit_RestrictReferences` for both) every reference must carry `Allowed="True"`, else [`MSKITRES003`](./reference/codes.md#mskitres003) / [`MSKITRES004`](./reference/codes.md#mskitres004). Off by default.
 
-**Prerelease dependencies on a stable branch.** On a stable branch a reference to a prerelease version of a package whose id starts with `MSKit_PrereleasePackagePrefix` (owner layer: `DragoAnt.`) warns with [`MSKIT_PRE001`](./reference/codes.md#mskitpre001); `MSKit_PrereleasePackageCheckAsWarning=false` makes it an error.
+**Prerelease dependencies on a stable branch.** On a stable branch a reference to a prerelease version of a package whose id starts with `MSKit_PrereleasePackagePrefix` (owner layer: `DragoAnt.`) warns with [`MSKITPRE001`](./reference/codes.md#mskitpre001); `MSKit_PrereleasePackageCheckAsWarning=false` makes it an error.
 
-**`TreatWarningsAsErrors` drift.** On a developer machine a csproj that changes the shared `TreatWarningsAsErrors` fails with [`MSKIT_SHARED020`](./reference/codes.md#mskitshared020); `MSKit_SkipAudit_TreatWarningsAsErrors=True` allows it.
+**`TreatWarningsAsErrors` drift.** On a developer machine a csproj that changes the shared `TreatWarningsAsErrors` fails with [`MSKITSHARED020`](./reference/codes.md#mskitshared020); `MSKit_SkipAudit_TreatWarningsAsErrors=True` allows it.
 
 ## Private references
 
diff --git a/docs/customizing.md b/docs/customizing.md
index 92d1eeb..351030a 100644
--- a/docs/customizing.md
+++ b/docs/customizing.md
@@ -32,7 +32,7 @@ Almost every default is written as `<X Condition="'$(X)'==''">`, so the first va
 | `MSKit_TestingFramework`, `MSKit_TestsAssertions` | `xunit.v3`, `AwesomeAssertions` | [Testing](./testing.md) |
 | `MSKit_RestrictPackageReference` | `Moq` as an error | [reference checks](./build.md#reference-checks) |
 
-**Another owner:** fork the kit, change `kit/.toolkit/msbuild/init.company.props` (and `.targets`) and `kit/.toolkit/res/package.icon.png`, publish releases from the fork and install with `update.sh --repo <owner>/<fork>` (recorded in `kit.json`, so later updates come from the fork). No part names an owner.
+**Another owner:** fork the kit, change `kit/.toolkit/msbuild/init.company.props` (and `.targets`) and `kit/.toolkit/res/package.icon.png`, publish releases from the fork and install with `update.sh --repo <owner>/<fork>` (recorded in `kit.json`, so later updates come from the fork). Set `MSKit_CodesHelpBaseUrl` in the owner layer to point the code links at the fork's code reference. No part names an owner.
 
 ## Extension files
 
diff --git a/docs/getting-started.md b/docs/getting-started.md
index 87c4a61..b3feba8 100644
--- a/docs/getting-started.md
+++ b/docs/getting-started.md
@@ -88,7 +88,7 @@ A project whose name ends in `.Tests` is a test project: [xUnit v3](https://xuni
 </Project>
 ```
 
-With [central package management](https://learn.microsoft.com/nuget/consume-packages/central-package-management), leave the test packages out of `Directory.Packages.props`: the kit provides their versions ([`MSKIT_DUP001`](./reference/codes.md#mskitdup001) reports a duplicate).
+With [central package management](https://learn.microsoft.com/nuget/consume-packages/central-package-management), leave the test packages out of `Directory.Packages.props`: the kit provides their versions ([`MSKITDUP001`](./reference/codes.md#mskitdup001) reports a duplicate).
 
 ## 5 Build, test, pack
 
diff --git a/docs/migrating-from-msbuild-routine.md b/docs/migrating-from-msbuild-routine.md
index d90eab4..be3fa6a 100644
--- a/docs/migrating-from-msbuild-routine.md
+++ b/docs/migrating-from-msbuild-routine.md
@@ -5,7 +5,7 @@
 1. **Remove the submodule:** `git rm .msbuild`, delete `.gitmodules`, and drop `submodules:` from your workflows.
 2. **Install the kit** ([Getting started](./getting-started.md)), with `--add PackageAsProj` if you use `Directory.PackageAsProj.targets`, and replace the `.msbuild\shared\init.props` / `init.targets` imports with the `.toolkit/msbuild/` ones.
 3. **Drop what is now a default:** `Copyright`, `PackageLicenseExpression`, `RepositoryUrl`, `PackageReleaseNotes`, `TargetFrameworkStrategy`, and the `.msbuild\tfm.constants.props` import.
-4. **Remove the versions the kit provides** from `Directory.Packages.props` (`xunit.v3*`, `xunit.runner.visualstudio`, `Microsoft.NET.Test.Sdk`, `Microsoft.Testing.Extensions.CodeCoverage`, `NSubstitute*`, your assertion library, `coverlet.collector`) and the explicit `Microsoft.Testing.Extensions.CodeCoverage` references from test projects; [`MSKIT_DUP001`](./reference/codes.md#mskitdup001) lists any you missed. To keep FluentAssertions 7, set `MSKit_TestsAssertions=FluentAssertions`.
+4. **Remove the versions the kit provides** from `Directory.Packages.props` (`xunit.v3*`, `xunit.runner.visualstudio`, `Microsoft.NET.Test.Sdk`, `Microsoft.Testing.Extensions.CodeCoverage`, `NSubstitute*`, your assertion library, `coverlet.collector`) and the explicit `Microsoft.Testing.Extensions.CodeCoverage` references from test projects; [`MSKITDUP001`](./reference/codes.md#mskitdup001) lists any you missed. To keep FluentAssertions 7, set `MSKit_TestsAssertions=FluentAssertions`.
 5. **Add `Directory.Version.props`** with the next `VersionPrefix`, and publish releases with tags such as `v2.0.1` ([Versioning](./versioning.md)).
 
 Renamed properties:
diff --git a/docs/optional-parts.md b/docs/optional-parts.md
index d2a26d0..84fa5be 100644
--- a/docs/optional-parts.md
+++ b/docs/optional-parts.md
@@ -19,8 +19,8 @@ The kit imports `Directory.PackageAsProj.targets` from the solution folder when
 
 | Code | When |
 | --- | --- |
-| [`MSKIT_PAP001`](./reference/codes.md#mskitpap001) | a package switched to a project is still resolved from the package: restore with `--force` |
-| [`MSKIT_PAP002`](./reference/codes.md#mskitpap002) | a package switched back is not restored yet: restore with `--force`, or set `PackageAsProj_SkipChecks=True` |
+| [`MSKITPAP001`](./reference/codes.md#mskitpap001) | a package switched to a project is still resolved from the package: restore with `--force` |
+| [`MSKITPAP002`](./reference/codes.md#mskitpap002) | a package switched back is not restored yet: restore with `--force`, or set `PackageAsProj_SkipChecks=True` |
 
 Keep `Directory.PackageAsProj.targets` out of git if the paths point at your own checkouts.
 
diff --git a/docs/package-readme.md b/docs/package-readme.md
index 4992077..2e4753c 100644
--- a/docs/package-readme.md
+++ b/docs/package-readme.md
@@ -18,7 +18,7 @@ The path is relative to the git root (or absolute). It wins over a `package.read
 3. **`<!-- nuget:only <PackageId> -->` … `<!-- /nuget:only -->`** blocks stay only in the readme of the packages they name (several ids: separate with spaces or commas). Unmarked content goes to every package, so a multi-package repository keeps one README.
 4. **The title is the package id.** The first level-1 heading (`# …`, or a `===`-underlined one) becomes `# <PackageId>`, so each package of a multi-package repository is named on its own page; a README with no level-1 heading gets the title as its first line. Only the content this package keeps counts: a heading inside a `nuget:skip` block, another package's `nuget:only` block or a code fence is never the one replaced. Set `MSKit_PackageReadmeTitle` to another title, or empty to keep the README's own heading.
 5. **Release notes and Issues links** are added to the overview when it does not already link those pages: the `## Overview` section when there is one, else the text above the first `##` heading.
-6. The `MSKIT_PKG` checks then run on the generated file, so a link the generator could not rewrite is still caught by `MSKIT_PKG017` / `MSKIT_PKG009`.
+6. The `MSKITPKG` checks then run on the generated file, so a link the generator could not rewrite is still caught by `MSKITPKG017` / `MSKITPKG009`.
 
 The markers are matched on lines of their own, outside code fences. A README that documents the markers in a fenced block is safe.
 
@@ -55,7 +55,7 @@ A self-hosted GitLab is recognised through the same item Source Link uses:
 | `MSKit_ReleasesUrl` | `auto` | The release-notes page, also the default `PackageReleaseNotes` off GitHub; empty leaves the link out |
 | `MSKit_IssuesUrl` | `auto` | The issues page; empty leaves the link out |
 | `MSKit_PackageReadmeTitle` | `auto` (the `PackageId`) | The text of the first level-1 heading; empty keeps the README's own heading |
-| `MSKit_RepositoryVisibility` | `$(CI_PROJECT_VISIBILITY)` | `private` or `internal` raises `MSKIT_PKG022` |
+| `MSKit_RepositoryVisibility` | `$(CI_PROJECT_VISIBILITY)` | `private` or `internal` raises `MSKITPKG022` |
 | `MSKit_GeneratedPackageReadmePath` | `obj/<Configuration>/package.readme.md` | Where the generated file goes |
 | `MSKit_PackageReadmeAllowedImageHosts` | the kit's list | `;`-separated hosts that replace the list below |
 
@@ -73,14 +73,14 @@ These stay warnings on CI; skip one with `MSKit_SkipPackageChecks` or `NoWarn` l
 
 | Code | Fires when |
 | --- | --- |
-| [`MSKIT_PKG020`](./reference/codes.md#mskitpkg020) | the README is missing, a marker is unbalanced, a path leaves the repository, or links cannot be rewritten (no repository URL, an unknown host, no commit) |
-| [`MSKIT_PKG021`](./reference/codes.md#mskitpkg021) | an image is served from a host nuget.org does not render images from; the warning names the image and its README line |
-| [`MSKIT_PKG022`](./reference/codes.md#mskitpkg022) | the repository is private or internal, so the links will not open for package readers |
+| [`MSKITPKG020`](./reference/codes.md#mskitpkg020) | the README is missing, a marker is unbalanced, a path leaves the repository, or links cannot be rewritten (no repository URL, an unknown host, no commit) |
+| [`MSKITPKG021`](./reference/codes.md#mskitpkg021) | an image is served from a host nuget.org does not render images from; the warning names the image and its README line |
+| [`MSKITPKG022`](./reference/codes.md#mskitpkg022) | the repository is private or internal, so the links will not open for package readers |
 
 ## Allowed image hosts
 
-nuget.org shows readme images only from [a fixed list of hosts](https://learn.microsoft.com/nuget/nuget-org/package-readme-on-nuget-org#allowed-domains-for-images-and-badges). The kit ships that list as `.toolkit/msbuild/DragoAnt.MSBuildKit.Packaging/nuget.allowed-image-hosts.txt` (copied from the page on 2026-10-05) and refreshes it with kit releases; nothing is downloaded during a build. `raw.githubusercontent.com` and `gitlab.com` are on it, so images from a GitHub or gitlab.com repository render; a self-hosted GitLab is not, and its images raise `MSKIT_PKG021`.
+nuget.org shows readme images only from [a fixed list of hosts](https://learn.microsoft.com/nuget/nuget-org/package-readme-on-nuget-org#allowed-domains-for-images-and-badges). The kit ships that list as `.toolkit/msbuild/DragoAnt.MSBuildKit.Packaging/nuget.allowed-image-hosts.txt` (copied from the page on 2026-10-05) and refreshes it with kit releases; nothing is downloaded during a build. `raw.githubusercontent.com` and `gitlab.com` are on it, so images from a GitHub or gitlab.com repository render; a self-hosted GitLab is not, and its images raise `MSKITPKG021`.
 
 ## Build cost
 
-The generator runs on `dotnet pack` only, once per project (before `GenerateNuspec`), never on `dotnet build`, a design-time build or a per-framework inner build. It is incremental: the README, the kit's host list and a stamp of the settings above are its inputs, so a second pack with nothing changed skips it. One in-process pass, no network, no process started. The generator and the `MSKIT_PKG` checks are one inline task, so a pack compiles it once whichever of the two runs.
+The generator runs on `dotnet pack` only, once per project (before `GenerateNuspec`), never on `dotnet build`, a design-time build or a per-framework inner build. It is incremental: the README, the kit's host list and a stamp of the settings above are its inputs, so a second pack with nothing changed skips it. One in-process pass, no network, no process started. The generator and the `MSKITPKG` checks are one inline task, so a pack compiles it once whichever of the two runs.
diff --git a/docs/packaging.md b/docs/packaging.md
index 988d545..1c86cfa 100644
--- a/docs/packaging.md
+++ b/docs/packaging.md
@@ -40,26 +40,26 @@ Set `MSKit_PackageValidationBaselineVersion` to the last published version once
 
 | Code | Fires when |
 | --- | --- |
-| [`MSKIT_PKG001`](./reference/codes.md#mskitpkg001) | `Description` is missing, the SDK default, or the package id |
-| [`MSKIT_PKG002`](./reference/codes.md#mskitpkg002) | `Description` is shorter than `MSKit_PackageDescriptionMinLength` (30) |
-| [`MSKIT_PKG003`](./reference/codes.md#mskitpkg003) | no README is packed |
-| [`MSKIT_PKG004`](./reference/codes.md#mskitpkg004) | no `PackageTags` |
-| [`MSKIT_PKG005`](./reference/codes.md#mskitpkg005) | no icon |
-| [`MSKIT_PKG006`](./reference/codes.md#mskitpkg006) | no licence expression or file |
-| [`MSKIT_PKG007`](./reference/codes.md#mskitpkg007) | the deprecated `PackageLicenseUrl` is set |
-| [`MSKIT_PKG008`](./reference/codes.md#mskitpkg008) | the deprecated `PackageIconUrl` is set |
-| [`MSKIT_PKG009`](./reference/codes.md#mskitpkg009) | the README has relative images |
-| [`MSKIT_PKG010`](./reference/codes.md#mskitpkg010) | the README contains HTML |
-| [`MSKIT_PKG011`](./reference/codes.md#mskitpkg011) | the README uses GitHub alerts (`> [!NOTE]`) |
-| [`MSKIT_PKG012`](./reference/codes.md#mskitpkg012) | the README loads images from a host nuget.org blocks |
-| [`MSKIT_PKG013`](./reference/codes.md#mskitpkg013) | the version is not SemVer 2.0 (`MSKit_SemVerRegex`) |
-| [`MSKIT_PKG014`](./reference/codes.md#mskitpkg014) | no repository or project URL |
-| [`MSKIT_PKG015`](./reference/codes.md#mskitpkg015) | the icon is not a 128×128 PNG or JPEG (`MSKit_PackageIconSize`) |
-| [`MSKIT_PKG016`](./reference/codes.md#mskitpkg016) | no `PackageReleaseNotes` |
-| [`MSKIT_PKG017`](./reference/codes.md#mskitpkg017) | the README has relative links |
-| [`MSKIT_PKG018`](./reference/codes.md#mskitpkg018) | an open-source licence with an "All rights reserved" copyright |
-| [`MSKIT_PKG019`](./reference/codes.md#mskitpkg019) | the README contains a Mermaid diagram |
+| [`MSKITPKG001`](./reference/codes.md#mskitpkg001) | `Description` is missing, the SDK default, or the package id |
+| [`MSKITPKG002`](./reference/codes.md#mskitpkg002) | `Description` is shorter than `MSKit_PackageDescriptionMinLength` (30) |
+| [`MSKITPKG003`](./reference/codes.md#mskitpkg003) | no README is packed |
+| [`MSKITPKG004`](./reference/codes.md#mskitpkg004) | no `PackageTags` |
+| [`MSKITPKG005`](./reference/codes.md#mskitpkg005) | no icon |
+| [`MSKITPKG006`](./reference/codes.md#mskitpkg006) | no licence expression or file |
+| [`MSKITPKG007`](./reference/codes.md#mskitpkg007) | the deprecated `PackageLicenseUrl` is set |
+| [`MSKITPKG008`](./reference/codes.md#mskitpkg008) | the deprecated `PackageIconUrl` is set |
+| [`MSKITPKG009`](./reference/codes.md#mskitpkg009) | the README has relative images |
+| [`MSKITPKG010`](./reference/codes.md#mskitpkg010) | the README contains HTML |
+| [`MSKITPKG011`](./reference/codes.md#mskitpkg011) | the README uses GitHub alerts (`> [!NOTE]`) |
+| [`MSKITPKG012`](./reference/codes.md#mskitpkg012) | the README loads images from a host nuget.org blocks |
+| [`MSKITPKG013`](./reference/codes.md#mskitpkg013) | the version is not SemVer 2.0 (`MSKit_SemVerRegex`) |
+| [`MSKITPKG014`](./reference/codes.md#mskitpkg014) | no repository or project URL |
+| [`MSKITPKG015`](./reference/codes.md#mskitpkg015) | the icon is not a 128×128 PNG or JPEG (`MSKit_PackageIconSize`) |
+| [`MSKITPKG016`](./reference/codes.md#mskitpkg016) | no `PackageReleaseNotes` |
+| [`MSKITPKG017`](./reference/codes.md#mskitpkg017) | the README has relative links |
+| [`MSKITPKG018`](./reference/codes.md#mskitpkg018) | an open-source licence with an "All rights reserved" copyright |
+| [`MSKITPKG019`](./reference/codes.md#mskitpkg019) | the README contains a Mermaid diagram |
 
-Images, links, HTML and alerts inside a fenced block or inline code are ignored; a GitHub Actions workflow badge from `github.com` counts as an allowed image. The readme generator adds three warnings of its own, `MSKIT_PKG020`-`022`, which stay warnings on CI ([Package readme](./package-readme.md#warnings)).
+Images, links, HTML and alerts inside a fenced block or inline code are ignored; a GitHub Actions workflow badge from `github.com` counts as an allowed image. The readme generator adds three warnings of its own, `MSKITPKG020`-`022`, which stay warnings on CI ([Package readme](./package-readme.md#warnings)).
 
-**Skipping a check:** list its code in `MSKit_SkipPackageChecks` (`MSKIT_PKG004;MSKIT_PKG016`) or in `NoWarn`; `MSKit_SkipPackageChecks=All` skips them all. Set it in a csproj to skip for one package.
+**Skipping a check:** list its code in `MSKit_SkipPackageChecks` (`MSKITPKG004;MSKITPKG016`) or in `NoWarn`; `MSKit_SkipPackageChecks=All` skips them all. Set it in a csproj to skip for one package.
diff --git a/docs/parts.md b/docs/parts.md
index b905ffd..0f92001 100644
--- a/docs/parts.md
+++ b/docs/parts.md
@@ -8,7 +8,7 @@ The kit is split into parts, one folder each under `.toolkit/msbuild/` (`DragoAn
 | `Trunk` | default | | Language defaults, product and copyright, the version engine, global usings, reference and consistency checks | [Build](./build.md), [Versioning](./versioning.md) |
 | `Vcs.GitHub` | default | | Reads the GitHub Actions variables: CI detection, run number, tag, pull request, repository URL | [Versioning](./versioning.md#ci-variables) |
 | `TfmConstants` | default | | `IsNET8`, `IsNET8_OR_GREATER`, `IsNETSTANDARD` and the rest, for conditions | [Build](./build.md#target-framework-constants) |
-| `Packaging` | default | | nuget.org metadata defaults, the readme generator and the `MSKIT_PKG` checks | [Packaging](./packaging.md) |
+| `Packaging` | default | | nuget.org metadata defaults, the readme generator and the `MSKITPKG` checks | [Packaging](./packaging.md) |
 | `Testing` | default | | Test-project detection, Microsoft.Testing.Platform, assertions, mocking, `InternalsVisibleTo` | [Testing](./testing.md) |
 | `Testing.XUnit.v3` | default | `Testing` | The xUnit v3 wiring | [Testing](./testing.md) |
 | `Locals.Secrets`, `Locals.DirectorySecrets`, `Locals.Compile` | default | | Secrets and source files that stay on the developer's machine | [Local files](./local-files.md) |
diff --git a/docs/reference/codes.md b/docs/reference/codes.md
index d7f5557..bea7a21 100644
--- a/docs/reference/codes.md
+++ b/docs/reference/codes.md
@@ -1,6 +1,8 @@
 # Code reference
 
-Every warning and error the kit reports, one section per code. The kit reports each code as `MSKIT_<FAMILY><nnn>` (for example `MSKIT_VER006`); the section anchors use the id without the underscore (`#mskitver006`). Severity is the default; the section says how to change or skip it.
+Every warning and error the kit reports, one section per code. A code is the kit prefix, a family and a three-digit number with no separator (`MSKITVER006`); its section anchor is the code in lower case (`#mskitver006`). Every warning and error carries a `HelpLink` to its section, which the terminal logger and IDEs show as a link on the code; `MSKit_CodesHelpBaseUrl` names the page the links point at ([property reference](./properties.md#machine-ci-and-paths)). Severity is the default; the section says how to change or skip it.
+
+Earlier releases put an underscore between the prefix and the family; each section names its former spelling, and `NoWarn`, `WarningsAsErrors`, `WarningsNotAsErrors` or `MSKit_SkipPackageChecks` entries that use it no longer match. A code is never renumbered or reused: `VER003` is reserved, and no release reported it.
 
 | Family | Part | Codes |
 | --- | --- | --- |
@@ -18,91 +20,91 @@ Every warning and error the kit reports, one section per code. The kit reports e
 
 ### MSKITPKG001
 
-`MSKIT_PKG001` — the package has no real `Description`: it is empty, the SDK's `Package Description`, the package id or the project name. Write one or two sentences on what the package does and what sets it apart; nuget.org search shows it first.
+`MSKITPKG001` (formerly `MSKIT_PKG001`) — the package has no real `Description`: it is empty, the SDK's `Package Description`, the package id or the project name. Write one or two sentences on what the package does and what sets it apart; nuget.org search shows it first.
 
 ### MSKITPKG002
 
-`MSKIT_PKG002` — `Description` is shorter than `MSKit_PackageDescriptionMinLength` (30 characters). Say what it does and for whom, or lower the bar.
+`MSKITPKG002` (formerly `MSKIT_PKG002`) — `Description` is shorter than `MSKit_PackageDescriptionMinLength` (30 characters). Say what it does and for whom, or lower the bar.
 
 ### MSKITPKG003
 
-`MSKIT_PKG003` — no README is packed. Add `package.readme.md` (or `README.md`) next to the csproj, or set `MSKit_PackageReadmeFrom`.
+`MSKITPKG003` (formerly `MSKIT_PKG003`) — no README is packed. Add `package.readme.md` (or `README.md`) next to the csproj, or set `MSKit_PackageReadmeFrom`.
 
 ### MSKITPKG004
 
-`MSKIT_PKG004` — no `PackageTags`. Add a few search terms that are not already in the package id.
+`MSKITPKG004` (formerly `MSKIT_PKG004`) — no `PackageTags`. Add a few search terms that are not already in the package id.
 
 ### MSKITPKG005
 
-`MSKIT_PKG005` — no icon. Set `PackageIconPath` to a 128×128 PNG or JPEG, packed as `icon<extension, lowercased>`; the owner layer sets one for every package.
+`MSKITPKG005` (formerly `MSKIT_PKG005`) — no icon. Set `PackageIconPath` to a 128×128 PNG or JPEG, packed as `icon<extension, lowercased>`; the owner layer sets one for every package.
 
 ### MSKITPKG006
 
-`MSKIT_PKG006` — no licence. Set `PackageLicenseExpression` to an [SPDX id](https://spdx.org/licenses/) or `PackageLicenseFile`.
+`MSKITPKG006` (formerly `MSKIT_PKG006`) — no licence. Set `PackageLicenseExpression` to an [SPDX id](https://spdx.org/licenses/) or `PackageLicenseFile`.
 
 ### MSKITPKG007
 
-`MSKIT_PKG007` — the deprecated `PackageLicenseUrl` is set. Use `PackageLicenseExpression` or `PackageLicenseFile`.
+`MSKITPKG007` (formerly `MSKIT_PKG007`) — the deprecated `PackageLicenseUrl` is set. Use `PackageLicenseExpression` or `PackageLicenseFile`.
 
 ### MSKITPKG008
 
-`MSKIT_PKG008` — the deprecated `PackageIconUrl` is set. Pack the image and use `PackageIcon` or `PackageIconPath`.
+`MSKITPKG008` (formerly `MSKIT_PKG008`) — the deprecated `PackageIconUrl` is set. Pack the image and use `PackageIcon` or `PackageIconPath`.
 
 ### MSKITPKG009
 
-`MSKIT_PKG009` — the package README has relative images, which nuget.org does not render. Use absolute `https` URLs from an [allowed host](https://learn.microsoft.com/nuget/nuget-org/package-readme-on-nuget-org#allowed-domains-for-images-and-badges), or generate the readme with `MSKit_PackageReadmeFrom`.
+`MSKITPKG009` (formerly `MSKIT_PKG009`) — the package README has relative images, which nuget.org does not render. Use absolute `https` URLs from an [allowed host](https://learn.microsoft.com/nuget/nuget-org/package-readme-on-nuget-org#allowed-domains-for-images-and-badges), or generate the readme with `MSKit_PackageReadmeFrom`.
 
 ### MSKITPKG010
 
-`MSKIT_PKG010` — the package README contains HTML, which nuget.org does not render. Use Markdown.
+`MSKITPKG010` (formerly `MSKIT_PKG010`) — the package README contains HTML, which nuget.org does not render. Use Markdown.
 
 ### MSKITPKG011
 
-`MSKIT_PKG011` — the package README uses GitHub alerts (`> [!NOTE]`), which nuget.org shows as plain quotes. Use a bold lead-in such as `**Note:**`.
+`MSKITPKG011` (formerly `MSKIT_PKG011`) — the package README uses GitHub alerts (`> [!NOTE]`), which nuget.org shows as plain quotes. Use a bold lead-in such as `**Note:**`.
 
 ### MSKITPKG012
 
-`MSKIT_PKG012` — the package README loads images from a host nuget.org blocks. Host them on an allowed domain (`img.shields.io`, `raw.githubusercontent.com`, …).
+`MSKITPKG012` (formerly `MSKIT_PKG012`) — the package README loads images from a host nuget.org blocks. Host them on an allowed domain (`img.shields.io`, `raw.githubusercontent.com`, …).
 
 ### MSKITPKG013
 
-`MSKIT_PKG013` — the package version is not [SemVer 2.0](https://semver.org/) (`MSKit_SemVerRegex`).
+`MSKITPKG013` (formerly `MSKIT_PKG013`) — the package version is not [SemVer 2.0](https://semver.org/) (`MSKit_SemVerRegex`).
 
 ### MSKITPKG014
 
-`MSKIT_PKG014` — no repository or project URL. Set `RepositoryUrl`, or build from a git clone whose `origin` remote Source Link can read.
+`MSKITPKG014` (formerly `MSKIT_PKG014`) — no repository or project URL. Set `RepositoryUrl`, or build from a git clone whose `origin` remote Source Link can read.
 
 ### MSKITPKG015
 
-`MSKIT_PKG015` — the icon is not a PNG or JPEG of `MSKit_PackageIconSize` × `MSKit_PackageIconSize` pixels (128); the size is checked on both formats.
+`MSKITPKG015` (formerly `MSKIT_PKG015`) — the icon is not a PNG or JPEG of `MSKit_PackageIconSize` × `MSKit_PackageIconSize` pixels (128); the size is checked on both formats.
 
 ### MSKITPKG016
 
-`MSKIT_PKG016` — no `PackageReleaseNotes`. The kit fills them on `github.com`, and on any host the generated readme knows with `MSKit_PackageReadmeFrom`; elsewhere set them (a link to the changelog is enough).
+`MSKITPKG016` (formerly `MSKIT_PKG016`) — no `PackageReleaseNotes`. The kit fills them on `github.com`, and on any host the generated readme knows with `MSKit_PackageReadmeFrom`; elsewhere set them (a link to the changelog is enough).
 
 ### MSKITPKG017
 
-`MSKIT_PKG017` — the package README has relative links, which break on nuget.org. Use absolute URLs, or generate the readme with `MSKit_PackageReadmeFrom`.
+`MSKITPKG017` (formerly `MSKIT_PKG017`) — the package README has relative links, which break on nuget.org. Use absolute URLs, or generate the readme with `MSKit_PackageReadmeFrom`.
 
 ### MSKITPKG018
 
-`MSKIT_PKG018` — the package has an open-source licence expression, but its `Copyright` says "all rights reserved". Use `Copyright (c) YEAR OWNER`.
+`MSKITPKG018` (formerly `MSKIT_PKG018`) — the package has an open-source licence expression, but its `Copyright` says "all rights reserved". Use `Copyright (c) YEAR OWNER`.
 
 ### MSKITPKG019
 
-`MSKIT_PKG019` — the package README contains a Mermaid diagram, which nuget.org shows as code. Link to the diagram on the repository host instead.
+`MSKITPKG019` (formerly `MSKIT_PKG019`) — the package README contains a Mermaid diagram, which nuget.org shows as code. Link to the diagram on the repository host instead.
 
 ### MSKITPKG020
 
-`MSKIT_PKG020` (warning) — the readme cannot be generated as asked: the `MSKit_PackageReadmeFrom` file is missing, a `nuget:skip` / `nuget:only` marker is unbalanced, a link leaves the repository, or links cannot be rewritten (no repository URL, an unknown host or provider, no commit). The message names the line.
+`MSKITPKG020` (formerly `MSKIT_PKG020`) (warning) — the readme cannot be generated as asked: the `MSKit_PackageReadmeFrom` file is missing, a `nuget:skip` / `nuget:only` marker is unbalanced, a link leaves the repository, or links cannot be rewritten (no repository URL, an unknown host or provider, no commit). The message names the line.
 
 ### MSKITPKG021
 
-`MSKIT_PKG021` (warning) — a generated readme loads an image from a host nuget.org does not render images from; the message names the image and its README line.
+`MSKITPKG021` (formerly `MSKIT_PKG021`) (warning) — a generated readme loads an image from a host nuget.org does not render images from; the message names the image and its README line.
 
 ### MSKITPKG022
 
-`MSKIT_PKG022` (warning) — the repository is private or internal (`MSKit_RepositoryVisibility`, else GitLab's `CI_PROJECT_VISIBILITY`), so the readme's links will not open for package readers.
+`MSKITPKG022` (formerly `MSKIT_PKG022`) (warning) — the repository is private or internal (`MSKit_RepositoryVisibility`, else GitLab's `CI_PROJECT_VISIBILITY`), so the readme's links will not open for package readers.
 
 ## Versioning
 
@@ -110,23 +112,23 @@ Background: [Versioning](../versioning.md).
 
 ### MSKITVER001
 
-`MSKIT_VER001` (error) — the csproj declares `<Version>` while a template strategy renders the version, so the value would be ignored. Remove it and declare `VersionPrefix` in `Directory.Version.props`, or set `MSKit_VersionStrategy=Manual`.
+`MSKITVER001` (formerly `MSKIT_VER001`) (error) — the csproj declares `<Version>` while a template strategy renders the version, so the value would be ignored. Remove it and declare `VersionPrefix` in `Directory.Version.props`, or set `MSKit_VersionStrategy=Manual`.
 
 ### MSKITVER002
 
-`MSKIT_VER002` (error) — a version template uses an unknown placeholder. The message lists the valid ones ([placeholders](../versioning.md#placeholders)).
+`MSKITVER002` (formerly `MSKIT_VER002`) (error) — a version template uses an unknown placeholder. The message lists the valid ones ([placeholders](../versioning.md#placeholders)).
 
 ### MSKITVER004
 
-`MSKIT_VER004` (error) — `MSKit_VersionStrategy=VersionTag` but `VersionTag` is empty. Pass `-p:VersionTag=1.2.3`, or use `ReleaseTag`.
+`MSKITVER004` (formerly `MSKIT_VER004`) (error) — `MSKit_VersionStrategy=VersionTag` but `VersionTag` is empty. Pass `-p:VersionTag=1.2.3`, or use `ReleaseTag`.
 
 ### MSKITVER006
 
-`MSKIT_VER006` (error, stops restore) — a tag build whose tag, after removing a leading `v`, is not [SemVer 2.0](https://semver.org/) (`MSKit_ReleaseTagRegex`). Delete the tag and its release and tag again (`v2.1.0`, `v2.1.0-beta.1`).
+`MSKITVER006` (formerly `MSKIT_VER006`) (error, stops restore) — a tag build whose tag, after removing a leading `v`, is not [SemVer 2.0](https://semver.org/) (`MSKit_ReleaseTagRegex`). Delete the tag and its release and tag again (`v2.1.0`, `v2.1.0-beta.1`).
 
 ### MSKITVER007
 
-`MSKIT_VER007` (warning) — the tag's `MAJOR.MINOR.PATCH` differs from the `VersionPrefix` the repository declares. Bump `VersionPrefix` after the release so branch builds sort above it; `MSKit_SkipAudit_ReleaseTagPrefix=True` silences it.
+`MSKITVER007` (formerly `MSKIT_VER007`) (warning) — the tag's `MAJOR.MINOR.PATCH` differs from the `VersionPrefix` the repository declares. Bump `VersionPrefix` after the release so branch builds sort above it; `MSKit_SkipAudit_ReleaseTagPrefix=True` silences it.
 
 ## References
 
@@ -134,27 +136,27 @@ Background: [reference checks](../build.md#reference-checks), [central package v
 
 ### MSKITDUP001
 
-`MSKIT_DUP001` (error, stops restore) — `Directory.Packages.props` declares a `PackageVersion` the kit already provides. Delete the line; to pin another version set the kit's `MSKit_PackageVersion_*` property, or turn the kit's versions off with `MSKit_ImplicitPackageVersions=False`. `MSKit_SkipAudit_ImplicitPackageDuplicates=True` skips the check.
+`MSKITDUP001` (formerly `MSKIT_DUP001`) (error, stops restore) — `Directory.Packages.props` declares a `PackageVersion` the kit already provides. Delete the line; to pin another version set the kit's `MSKit_PackageVersion_*` property, or turn the kit's versions off with `MSKit_ImplicitPackageVersions=False`. `MSKit_SkipAudit_ImplicitPackageDuplicates=True` skips the check.
 
 ### MSKITPRE001
 
-`MSKIT_PRE001` (warning) — a stable-branch build references a prerelease version of a package whose id starts with `MSKit_PrereleasePackagePrefix`. Use a stable version; `MSKit_PrereleasePackageCheckAsWarning=false` makes it an error.
+`MSKITPRE001` (formerly `MSKIT_PRE001`) (warning) — a stable-branch build references a prerelease version of a package whose id starts with `MSKit_PrereleasePackagePrefix`. Use a stable version; `MSKit_PrereleasePackageCheckAsWarning=false` makes it an error.
 
 ### MSKITRES001
 
-`MSKIT_RES001` (error) — a referenced package is banned by an `MSKit_RestrictPackageReference` item with `Type="Error"`. Remove it or use the suggested alternative; `SkipGlobalRestriction="True"` on the one `PackageReference` turns it into a warning.
+`MSKITRES001` (formerly `MSKIT_RES001`) (error) — a referenced package is banned by an `MSKit_RestrictPackageReference` item with `Type="Error"`. Remove it or use the suggested alternative; `SkipGlobalRestriction="True"` on the one `PackageReference` turns it into a warning.
 
 ### MSKITRES002
 
-`MSKIT_RES002` (warning) — a referenced package is discouraged by an `MSKit_RestrictPackageReference` item with `Type="Warning"`. `SkipGlobalRestriction="True"` on the reference silences it.
+`MSKITRES002` (formerly `MSKIT_RES002`) (warning) — a referenced package is discouraged by an `MSKit_RestrictPackageReference` item with `Type="Warning"`. `SkipGlobalRestriction="True"` on the reference silences it.
 
 ### MSKITRES003
 
-`MSKIT_RES003` (error) — with `MSKit_RestrictProjectReferences=True` (or `MSKit_RestrictReferences=True`), a `ProjectReference` lacks `Allowed="True"`.
+`MSKITRES003` (formerly `MSKIT_RES003`) (error) — with `MSKit_RestrictProjectReferences=True` (or `MSKit_RestrictReferences=True`), a `ProjectReference` lacks `Allowed="True"`.
 
 ### MSKITRES004
 
-`MSKIT_RES004` (error) — with `MSKit_RestrictPackageReferences=True` (or `MSKit_RestrictReferences=True`), a `PackageReference` lacks `Allowed="True"`.
+`MSKITRES004` (formerly `MSKIT_RES004`) (error) — with `MSKit_RestrictPackageReferences=True` (or `MSKit_RestrictReferences=True`), a `PackageReference` lacks `Allowed="True"`.
 
 ## Shared properties
 
@@ -162,27 +164,27 @@ Background: [target frameworks declared once](../build.md#target-frameworks-decl
 
 ### MSKITSHARED006
 
-`MSKIT_SHARED006` (error) — the csproj declares the same `TargetFramework` as `Directory.Build.props`. Delete it from the csproj.
+`MSKITSHARED006` (formerly `MSKIT_SHARED006`) (error) — the csproj declares the same `TargetFramework` as `Directory.Build.props`. Delete it from the csproj.
 
 ### MSKITSHARED007
 
-`MSKIT_SHARED007` (error) — the csproj declares the same `TargetFrameworks` as `Directory.Build.props`. Delete it from the csproj.
+`MSKITSHARED007` (formerly `MSKIT_SHARED007`) (error) — the csproj declares the same `TargetFrameworks` as `Directory.Build.props`. Delete it from the csproj.
 
 ### MSKITSHARED008
 
-`MSKIT_SHARED008` (warning) — the csproj overrides the shared `TargetFramework` with another value. Remove it, or accept it with `MSKit_SkipAudit_TargetFrameworkOverride=True` in the csproj.
+`MSKITSHARED008` (formerly `MSKIT_SHARED008`) (warning) — the csproj overrides the shared `TargetFramework` with another value. Remove it, or accept it with `MSKit_SkipAudit_TargetFrameworkOverride=True` in the csproj.
 
 ### MSKITSHARED009
 
-`MSKIT_SHARED009` (warning) — the csproj overrides the shared `TargetFrameworks` with another value. Remove it, or accept it with `MSKit_SkipAudit_TargetFrameworkOverride=True`.
+`MSKITSHARED009` (formerly `MSKIT_SHARED009`) (warning) — the csproj overrides the shared `TargetFrameworks` with another value. Remove it, or accept it with `MSKit_SkipAudit_TargetFrameworkOverride=True`.
 
 ### MSKITSHARED010
 
-`MSKIT_SHARED010` (error) — the csproj declares both `TargetFramework` and `TargetFrameworks` (an empty `<TargetFramework></TargetFramework>` counts). Keep one.
+`MSKITSHARED010` (formerly `MSKIT_SHARED010`) (error) — the csproj declares both `TargetFramework` and `TargetFrameworks` (an empty `<TargetFramework></TargetFramework>` counts). Keep one.
 
 ### MSKITSHARED020
 
-`MSKIT_SHARED020` (error, developer machines only) — the csproj's final `TreatWarningsAsErrors` differs from the shared value. Align it, or set `MSKit_SkipAudit_TreatWarningsAsErrors=True`.
+`MSKITSHARED020` (formerly `MSKIT_SHARED020`) (error, developer machines only) — the csproj's final `TreatWarningsAsErrors` differs from the shared value. Align it, or set `MSKit_SkipAudit_TreatWarningsAsErrors=True`.
 
 ## Project types
 
@@ -190,19 +192,19 @@ Background: [Roslyn components](../roslyn.md).
 
 ### MSKITCORE001
 
-`MSKIT_CORE001` (error) — the project name matches more than one detection regex (analyzer, code fix, source generator). Rename the project, narrow a `MSKit_*ProjectNameRegex`, or set the matching `MSKit_Disable*AutoDetect=true` in `Directory.Build.props` above the kit import.
+`MSKITCORE001` (formerly `MSKIT_CORE001`) (error) — the project name matches more than one detection regex (analyzer, code fix, source generator). Rename the project, narrow a `MSKit_*ProjectNameRegex`, or set the matching `MSKit_Disable*AutoDetect=true` in `Directory.Build.props` above the kit import.
 
 ### MSKITROSLYN001
 
-`MSKIT_ROSLYN001` (error) — the name matches the analyzer regex, but the `Project.CodeAnalyzer` part is not installed. `sh .toolkit/update.sh --add Project.CodeAnalyzer`, or rename the project, or set `MSKit_DisableCodeAnalyzerAutoDetect=true` in `Directory.Build.props` above the kit import.
+`MSKITROSLYN001` (formerly `MSKIT_ROSLYN001`) (error) — the name matches the analyzer regex, but the `Project.CodeAnalyzer` part is not installed. `sh .toolkit/update.sh --add Project.CodeAnalyzer`, or rename the project, or set `MSKit_DisableCodeAnalyzerAutoDetect=true` in `Directory.Build.props` above the kit import.
 
 ### MSKITROSLYN002
 
-`MSKIT_ROSLYN002` (error) — the name matches the code-fix regex, but `Project.CodeFixer` is not installed. Add the part, rename, or set `MSKit_DisableCodeFixerAutoDetect=true` in `Directory.Build.props` above the kit import.
+`MSKITROSLYN002` (formerly `MSKIT_ROSLYN002`) (error) — the name matches the code-fix regex, but `Project.CodeFixer` is not installed. Add the part, rename, or set `MSKit_DisableCodeFixerAutoDetect=true` in `Directory.Build.props` above the kit import.
 
 ### MSKITROSLYN003
 
-`MSKIT_ROSLYN003` (error) — the name matches the source-generator regex, but `Project.SourceGenerator` is not installed. Add the part, rename, or set `MSKit_DisableSourceGeneratorAutoDetect=true` in `Directory.Build.props` above the kit import.
+`MSKITROSLYN003` (formerly `MSKIT_ROSLYN003`) (error) — the name matches the source-generator regex, but `Project.SourceGenerator` is not installed. Add the part, rename, or set `MSKit_DisableSourceGeneratorAutoDetect=true` in `Directory.Build.props` above the kit import.
 
 ## Testing
 
@@ -210,55 +212,55 @@ Background: [Testing](../testing.md).
 
 ### MSKITTEST005
 
-`MSKIT_TEST005` (error) — an xUnit v3 test project targets a framework older than net8.0.
+`MSKITTEST005` (formerly `MSKIT_TEST005`) (error) — an xUnit v3 test project targets a framework older than net8.0.
 
 ### MSKITTEST010
 
-`MSKIT_TEST010` (error) — `$(TestsProjectCommonPropsPath)` was imported before `MSKit_TestingFramework` was set. Put the `PropertyGroup` above the `Import`.
+`MSKITTEST010` (formerly `MSKIT_TEST010`) (error) — `$(TestsProjectCommonPropsPath)` was imported before `MSKit_TestingFramework` was set. Put the `PropertyGroup` above the `Import`.
 
 ### MSKITTEST011
 
-`MSKIT_TEST011` (error) — `MSKit_TestingFramework` changed after `$(TestsProjectCommonPropsPath)` was imported. Move the `PropertyGroup` above the `Import`.
+`MSKITTEST011` (formerly `MSKIT_TEST011`) (error) — `MSKit_TestingFramework` changed after `$(TestsProjectCommonPropsPath)` was imported. Move the `PropertyGroup` above the `Import`.
 
 ### MSKITTEST012
 
-`MSKIT_TEST012` (error) — no wiring exists for the `MSKit_TestingFramework` of an explicit test project. Use `xunit.v3`, or point `MSKit_TestingFramework_CommonPropsPath` at your own props file.
+`MSKITTEST012` (formerly `MSKIT_TEST012`) (error) — no wiring exists for the `MSKit_TestingFramework` of an explicit test project. Use `xunit.v3`, or point `MSKit_TestingFramework_CommonPropsPath` at your own props file.
 
 ### MSKITTEST013
 
-`MSKIT_TEST013` (error) — the csproj sets `IsTestsProject` directly, too late for the props-phase wiring. Rename the project to match `MSKit_TestsProjectNameRegex`, or use the explicit endpoint `$(TestsProjectCommonPropsPath)`.
+`MSKITTEST013` (formerly `MSKIT_TEST013`) (error) — the csproj sets `IsTestsProject` directly, too late for the props-phase wiring. Rename the project to match `MSKit_TestsProjectNameRegex`, or use the explicit endpoint `$(TestsProjectCommonPropsPath)`.
 
 ### MSKITTEST014
 
-`MSKIT_TEST014` (error) — the name matches the test-project regex, but the project is marked as a test helper library. Rename it (`Acme.TestUtils`), narrow the regex, or drop the helper-library flag.
+`MSKITTEST014` (formerly `MSKIT_TEST014`) (error) — the name matches the test-project regex, but the project is marked as a test helper library. Rename it (`Acme.TestUtils`), narrow the regex, or drop the helper-library flag.
 
 ### MSKITTEST020
 
-`MSKIT_TEST020` (error) — `$(TestsLibProjectCommonPropsPath)` was imported before `MSKit_TestingFramework` was set.
+`MSKITTEST020` (formerly `MSKIT_TEST020`) (error) — `$(TestsLibProjectCommonPropsPath)` was imported before `MSKit_TestingFramework` was set.
 
 ### MSKITTEST021
 
-`MSKIT_TEST021` (error) — `MSKit_TestingFramework` changed after `$(TestsLibProjectCommonPropsPath)` was imported.
+`MSKITTEST021` (formerly `MSKIT_TEST021`) (error) — `MSKit_TestingFramework` changed after `$(TestsLibProjectCommonPropsPath)` was imported.
 
 ### MSKITTEST022
 
-`MSKIT_TEST022` (error) — no helper-library wiring exists for `MSKit_TestingFramework`. Use `xunit.v3`, or set `MSKit_TestingFramework_LibCommonPropsPath`.
+`MSKITTEST022` (formerly `MSKIT_TEST022`) (error) — no helper-library wiring exists for `MSKit_TestingFramework`. Use `xunit.v3`, or set `MSKit_TestingFramework_LibCommonPropsPath`.
 
 ### MSKITTEST025
 
-`MSKIT_TEST025` (error) — a test project or helper library has no `MSKit_TestingFramework`. Set it in `Directory.Build.props` (the owner layer sets `xunit.v3`).
+`MSKITTEST025` (formerly `MSKIT_TEST025`) (error) — a test project or helper library has no `MSKit_TestingFramework`. Set it in `Directory.Build.props` (the owner layer sets `xunit.v3`).
 
 ### MSKITTEST026
 
-`MSKIT_TEST026` (error) — no installed part wires the `MSKit_TestingFramework` value. Use `xunit.v3` (part `Testing.XUnit.v3`), or set `MSKit_TestingFramework_CommonPropsPath`.
+`MSKITTEST026` (formerly `MSKIT_TEST026`) (error) — no installed part wires the `MSKit_TestingFramework` value. Use `xunit.v3` (part `Testing.XUnit.v3`), or set `MSKit_TestingFramework_CommonPropsPath`.
 
 ### MSKITTEST030
 
-`MSKIT_TEST030` (warning) — `MSKit_TestsDir` is empty, so `InternalsVisibleTo` cannot be added. Set it, or turn `InternalsVisibleToAllTestsProjects` off.
+`MSKITTEST030` (formerly `MSKIT_TEST030`) (warning) — `MSKit_TestsDir` is empty, so `InternalsVisibleTo` cannot be added. Set it, or turn `InternalsVisibleToAllTestsProjects` off.
 
 ### MSKITTEST031
 
-`MSKIT_TEST031` (warning) — `MSKit_TestsDir` points at a folder that does not exist.
+`MSKITTEST031` (formerly `MSKIT_TEST031`) (warning) — `MSKit_TestsDir` points at a folder that does not exist.
 
 ## PackageAsProj
 
@@ -266,8 +268,8 @@ Background: [PackageAsProj](../optional-parts.md#packageasproj).
 
 ### MSKITPAP001
 
-`MSKIT_PAP001` (error) — a package switched to a `ProjectReference` is still resolved from the package. Run `dotnet restore --force`.
+`MSKITPAP001` (formerly `MSKIT_PAP001`) (error) — a package switched to a `ProjectReference` is still resolved from the package. Run `dotnet restore --force`.
 
 ### MSKITPAP002
 
-`MSKIT_PAP002` (error) — a package switched back from a project is not restored yet. Run `dotnet restore --force`, or set `PackageAsProj_SkipChecks=True`.
+`MSKITPAP002` (formerly `MSKIT_PAP002`) (error) — a package switched back from a project is not restored yet. Run `dotnet restore --force`, or set `PackageAsProj_SkipChecks=True`.
diff --git a/docs/reference/properties.md b/docs/reference/properties.md
index 6fe2a8b..868d637 100644
--- a/docs/reference/properties.md
+++ b/docs/reference/properties.md
@@ -29,6 +29,7 @@ Every property and item the kit sets or reads, grouped by topic. **Set** = a val
 | `MSKit_ProjectObjDir` | out | | The project's `obj` folder, absolute |
 | `MSKit_Templates` | set | `.toolkit/.local/` | Templates for local files ([Local files](../local-files.md)) |
 | `MSKit_Diagnostic` | set | `false` | Reserved; nothing reads it in this version |
+| `MSKit_CodesHelpBaseUrl` | set | `https://github.com/DragoAnt/MSBuildKit/blob/main/docs/reference/codes.md` | The page every warning and error links to (`HelpLink`); the link adds `#` and the code in lower case ([code reference](./codes.md)). Point it at your own copy of the page |
 
 ## Versioning
 
@@ -45,7 +46,7 @@ Every property and item the kit sets or reads, grouped by topic. **Set** = a val
 | `MSKit_IsReleaseTagValid` | out | | |
 | `MSKit_PullRequestNumber` | set | from `GITHUB_REF` / `GITHUB_REF_NAME` | `{prNumber}` |
 | `MSKit_BuildDateTimeUtc` | set | the environment variable of that name, else each project's own clock | One date for a whole build |
-| `MSKit_SkipAudit_ReleaseTagPrefix` | set | empty | `True` silences `MSKIT_VER007` |
+| `MSKit_SkipAudit_ReleaseTagPrefix` | set | empty | `True` silences `MSKITVER007` |
 
 ## Target frameworks
 
@@ -59,7 +60,7 @@ Every property and item the kit sets or reads, grouped by topic. **Set** = a val
 | `IsTfmConstantsImported` | out | | The constants file is loaded |
 | `MSKit_TargetFramework_Shared`, `MSKit_TargetFrameworks_Shared` | out | | The value declared in `Directory.Build.props` ([declared once](../build.md#target-frameworks-declared-once)) |
 | `MSKit_TargetFramework_Proj`, `MSKit_TargetFrameworks_Proj` | out | | The value declared in the csproj |
-| `MSKit_SkipAudit_TargetFrameworkOverride` | set | empty | `True` accepts a different csproj value (`MSKIT_SHARED008` / `009`) |
+| `MSKit_SkipAudit_TargetFrameworkOverride` | set | empty | `True` accepts a different csproj value (`MSKITSHARED008` / `009`) |
 | `MSKit_GuardXmlPeekRoutine`, `MSKit_GuardXmlPeekAudit` | set | empty (on) | `False` skips the text pre-check before parsing the csproj |
 
 ## Build defaults and reference checks
@@ -69,15 +70,15 @@ Every property and item the kit sets or reads, grouped by topic. **Set** = a val
 | `MSKit_IncludeCodeAnalysisGlobalUsings` | set | `True` | The kit's [global usings](../build.md#global-usings) |
 | `ExcludeFromCodeCoverage` | set | `True` for test projects | Adds `[ExcludeFromCodeCoverage]` to the assembly |
 | `MSKit_TreatWarningsAsErrors_Shared` | out | | `TreatWarningsAsErrors` before the csproj body |
-| `MSKit_SkipAudit_TreatWarningsAsErrors` | set | `True` on CI | Skips `MSKIT_SHARED020` |
+| `MSKit_SkipAudit_TreatWarningsAsErrors` | set | `True` on CI | Skips `MSKITSHARED020` |
 | `MSKit_ImplicitPackageVersions` | set | `True` | The kit's [package versions](../build.md#central-package-versions) |
-| `MSKit_SkipAudit_ImplicitPackageDuplicates` | set | `False` | `True` skips `MSKIT_DUP001` |
+| `MSKit_SkipAudit_ImplicitPackageDuplicates` | set | `False` | `True` skips `MSKITDUP001` |
 | `MSKit_RestrictPackageReference` | item | `Moq` (`Type="Error"`, owner layer) | A banned (`Type="Error"`) or discouraged (`Type="Warning"`) package, with a `Message` ([reference checks](../build.md#reference-checks)) |
 | `MSKit_PackageReferenceNotAllowed`, `MSKit_ProjectReferenceNotAllowed` | item | | The checks' findings; read-only |
 | `MSKit_RestrictReferences` | set | `False` | Allow-list mode for both reference kinds |
 | `MSKit_RestrictProjectReferences`, `MSKit_RestrictPackageReferences` | set | `MSKit_RestrictReferences` | Allow-list mode for one kind (`Allowed="True"` required) |
 | `MSKit_PrereleasePackagePrefix` | set | owner layer `DragoAnt.` | Ids the prerelease check covers |
-| `MSKit_PrereleasePackageCheckAsWarning` | set | `true` | `false` makes `MSKIT_PRE001` an error |
+| `MSKit_PrereleasePackageCheckAsWarning` | set | `true` | `false` makes `MSKITPRE001` an error |
 | `MSKit_ProjectReferenceAsPrivateAssets`, `MSKit_PackageReferenceAsPrivateAssets` | set | empty | `True` makes every reference of that kind private ([Build](../build.md#private-references)) |
 | `ManufacturerName`, `FullManufacturerName` | set | `DragoAnt` (owner layer, unconditional) | The owner ([Customizing](../customizing.md#the-owner-layer)) |
 
@@ -98,11 +99,11 @@ Every property and item the kit sets or reads, grouped by topic. **Set** = a val
 | `MSKit_PackageReadmeSourcePath` | set | `package.readme.md`, else `README.md` next to the csproj | The README packed as `readme.md` |
 | `MSKit_PackageValidationBaselineVersion` | set | empty | The release package validation compares against |
 | `MSKit_DefaultReleaseNotes` | set | empty (on) | `False` turns the `PackageReleaseNotes` default off |
-| `MSKit_PackageChecksAsErrors` | set | `True` on CI | The `MSKIT_PKG` checks as errors ([Packaging](../packaging.md#checks)) |
+| `MSKit_PackageChecksAsErrors` | set | `True` on CI | The `MSKITPKG` checks as errors ([Packaging](../packaging.md#checks)) |
 | `MSKit_SkipPackageChecks` | set | empty | Codes to skip, `;`-separated, or `All` |
-| `MSKit_PackageDescriptionMinLength` | set | `30` | `MSKIT_PKG002` |
-| `MSKit_PackageIconSize` | set | `128` | `MSKIT_PKG015` |
-| `MSKit_SemVerRegex` | set | SemVer 2.0 | `MSKIT_PKG013` |
+| `MSKit_PackageDescriptionMinLength` | set | `30` | `MSKITPKG002` |
+| `MSKit_PackageIconSize` | set | `128` | `MSKITPKG015` |
+| `MSKit_SemVerRegex` | set | SemVer 2.0 | `MSKITPKG013` |
 
 ## Package readme
 
@@ -114,7 +115,7 @@ Every property and item the kit sets or reads, grouped by topic. **Set** = a val
 | `MSKit_RepoProvider` | set | detected | `GitHub`, `GitLab`, `AzureDevOps`, `Bitbucket`, `Gitea` |
 | `MSKit_RepoBlobUrlTemplate`, `MSKit_RepoRawUrlTemplate` | set | the provider's | File-link and image templates |
 | `MSKit_ReleasesUrl`, `MSKit_IssuesUrl` | set | `auto` | The links added to the overview; empty leaves one out |
-| `MSKit_RepositoryVisibility` | set | `CI_PROJECT_VISIBILITY` | `private` / `internal` raises `MSKIT_PKG022` |
+| `MSKit_RepositoryVisibility` | set | `CI_PROJECT_VISIBILITY` | `private` / `internal` raises `MSKITPKG022` |
 | `MSKit_PackageReadmeAllowedImageHosts` | set | the hosts file | `;`-separated hosts that replace the file's list |
 | `MSKit_PackageReadmeAllowedImageHostsFile` | set | the kit's `nuget.allowed-image-hosts.txt` | The hosts file |
 
@@ -148,7 +149,7 @@ Every property and item the kit sets or reads, grouped by topic. **Set** = a val
 | `MSKit_CodeAnalyzerProjectNameRegex`, `MSKit_CodeFixerProjectNameRegex`, `MSKit_SourceGeneratorProjectNameRegex` | set | `\.Analyzers$`, `\.CodeFixes$`, `\.SourceGenerator$` | Role names |
 | `MSKit_DisableCodeAnalyzerAutoDetect`, `MSKit_DisableCodeFixerAutoDetect`, `MSKit_DisableSourceGeneratorAutoDetect` | set | empty | `true` above the kit import turns detection off |
 | `MSKit_IsCodeAnalyzerAutoDetected`, `MSKit_IsCodeFixerAutoDetected`, `MSKit_IsSourceGeneratorAutoDetected` | out | | The name matched |
-| `MSKit_AutoDetectedProjectType` | item | | Every role the name matched; more than one is `MSKIT_CORE001` |
+| `MSKit_AutoDetectedProjectType` | item | | Every role the name matched; more than one is `MSKITCORE001` |
 | `MSKit_CodeAnalyzerSatelliteAttached`, `MSKit_CodeFixerSatelliteAttached`, `MSKit_SourceGeneratorSatelliteAttached` | out | | The role's part is installed |
 | `CodeAnalyzerCommonPropsPath`, `CodeFixerCommonPropsPath`, `SourceGeneratorCommonPropsPath`, `RoslynComponentCommonPropsPath` | out | | The props a Roslyn project imports |
 | `MSKit_HasCodeFixer` | set | `True` | Look for the sibling code-fix project |
@@ -176,6 +177,6 @@ Every property and item the kit sets or reads, grouped by topic. **Set** = a val
 
 | Name | Kind | Default | Meaning |
 | --- | --- | --- | --- |
-| `PackageAsProj_SkipChecks` | set | empty | `True` skips `MSKIT_PAP002` ([PackageAsProj](../optional-parts.md#packageasproj)) |
+| `PackageAsProj_SkipChecks` | set | empty | `True` skips `MSKITPAP002` ([PackageAsProj](../optional-parts.md#packageasproj)) |
 | `ProjMetadataOutDir` | set | empty (off) | Where the metadata YAML goes ([ProjMetadata](../optional-parts.md#projmetadata)) |
 | `MSKit_EFScriptsDir` | out | | The EF scripts folder ([EF](../optional-parts.md#ef)) |
diff --git a/docs/roslyn.md b/docs/roslyn.md
index e7b0eb4..080d4ab 100644
--- a/docs/roslyn.md
+++ b/docs/roslyn.md
@@ -28,9 +28,9 @@ A project needs **both** of these:
 | code fix (`Acme.CodeFixes`) | `$(CodeFixerCommonPropsPath)` |
 | source generator (`Acme.SourceGenerator`) | `$(SourceGeneratorCommonPropsPath)` |
 
-The analyzer and code-fix props set their role themselves, so a project with another name only needs the import; a source generator with another name also sets `<IsSourceGenerator>true</IsSourceGenerator>` above it. Set your own `Description`: the analyzer's default, "Code analyzers description", fails [`MSKIT_PKG002`](./reference/codes.md#mskitpkg002).
+The analyzer and code-fix props set their role themselves, so a project with another name only needs the import; a source generator with another name also sets `<IsSourceGenerator>true</IsSourceGenerator>` above it. Set your own `Description`: the analyzer's default, "Code analyzers description", fails [`MSKITPKG002`](./reference/codes.md#mskitpkg002).
 
-A project whose name matches a role but whose part is not installed fails with [`MSKIT_ROSLYN001`](./reference/codes.md#mskitroslyn001)-[`003`](./reference/codes.md#mskitroslyn003); a name that matches two roles fails with [`MSKIT_CORE001`](./reference/codes.md#mskitcore001). Detection runs in the props phase, so to stop it set `MSKit_Disable<Role>AutoDetect=true` (`MSKit_DisableCodeAnalyzerAutoDetect`, …) or narrow the regex, in `Directory.Build.props` above the kit import; set in the csproj, as the error text suggests, it comes too late.
+A project whose name matches a role but whose part is not installed fails with [`MSKITROSLYN001`](./reference/codes.md#mskitroslyn001)-[`003`](./reference/codes.md#mskitroslyn003); a name that matches two roles fails with [`MSKITCORE001`](./reference/codes.md#mskitcore001). Detection runs in the props phase, so to stop it set `MSKit_Disable<Role>AutoDetect=true` (`MSKit_DisableCodeAnalyzerAutoDetect`, …) or narrow the regex, in `Directory.Build.props` above the kit import; set in the csproj, as the error text suggests, it comes too late.
 
 ## What the props set
 
@@ -38,7 +38,7 @@ Every role (`$(RoslynComponentCommonPropsPath)`, imported by the three above):
 
 | Setting | Value |
 | --- | --- |
-| `TargetFramework` | `netstandard2.0` (a shared `TargetFrameworks` is cleared, and the `MSKIT_SHARED008` override warning is skipped) |
+| `TargetFramework` | `netstandard2.0` (a shared `TargetFrameworks` is cleared, and the `MSKITSHARED008` override warning is skipped) |
 | `IsRoslynComponent`, `EnforceExtendedAnalyzerRules`, `DevelopmentDependency` | `True` |
 | `IsPackable` | `True` |
 | `IncludeBuildOutput`, `IncludeSymbols` | `False`: the dll goes to `analyzers/dotnet/cs/`, not `lib/` |
diff --git a/docs/testing.md b/docs/testing.md
index 9d495b7..8657d6d 100644
--- a/docs/testing.md
+++ b/docs/testing.md
@@ -9,7 +9,7 @@ The Testing and Testing.XUnit.v3 parts turn a project into a test project by its
 | test project | `MSKit_TestsProjectNameRegex`, default `\.(Tests(\.Integration\|\.Unit)?\|IntegrationTests\|UnitTests)$`: `Acme.Tests`, `Acme.Tests.Unit`, `Acme.Tests.Integration`, `Acme.UnitTests`, `Acme.IntegrationTests` | `IsTestsProject=True`: an executable test host, never packable |
 | test helper library | `MSKit_TestsLibProjectNameRegex`, default `\.(TestsSuite\|TestsFixtures\|Fixtures)$` | `IsTestsLibProject=True`: shared fixtures and base classes with the assertion and xUnit libraries, not runnable |
 
-Detection runs in the props phase, because the test framework's own targets read the result before `Directory.Build.targets`. So a project whose name does not match cannot just set `IsTestsProject` in its csproj — that fails with [`MSKIT_TEST013`](./reference/codes.md#mskittest013). Use the explicit endpoint instead:
+Detection runs in the props phase, because the test framework's own targets read the result before `Directory.Build.targets`. So a project whose name does not match cannot just set `IsTestsProject` in its csproj — that fails with [`MSKITTEST013`](./reference/codes.md#mskittest013). Use the explicit endpoint instead:
 
 ```xml
 <Project Sdk="Microsoft.NET.Sdk">
@@ -48,7 +48,7 @@ dotnet test --solution MyRepo.slnx -c Release --coverage --coverage-output-forma
 
 ## `InternalsVisibleTo`
 
-Every project that is neither a test project nor a helper library exposes its internals to **every** test project and helper library found under `MSKit_TestsDir` (default: the solution folder, else the git root), and to `DynamicProxyGenAssembly2`, so NSubstitute can mock internal types. `InternalsVisibleToAllTestsProjects=False` in a csproj turns it off for that project. [`MSKIT_TEST030`](./reference/codes.md#mskittest030) and [`MSKIT_TEST031`](./reference/codes.md#mskittest031) warn when `MSKit_TestsDir` is empty or missing.
+Every project that is neither a test project nor a helper library exposes its internals to **every** test project and helper library found under `MSKit_TestsDir` (default: the solution folder, else the git root), and to `DynamicProxyGenAssembly2`, so NSubstitute can mock internal types. `InternalsVisibleToAllTestsProjects=False` in a csproj turns it off for that project. [`MSKITTEST030`](./reference/codes.md#mskittest030) and [`MSKITTEST031`](./reference/codes.md#mskittest031) warn when `MSKit_TestsDir` is empty or missing.
 
 ## Package versions
 
@@ -73,8 +73,8 @@ The kit provides these versions ([Build](./build.md#central-package-versions));
 
 | Code | When |
 | --- | --- |
-| [`MSKIT_TEST005`](./reference/codes.md#mskittest005) | an xUnit v3 test project targets a framework older than net8.0 |
-| [`MSKIT_TEST010`](./reference/codes.md#mskittest010)-[`012`](./reference/codes.md#mskittest012), [`MSKIT_TEST020`](./reference/codes.md#mskittest020)-[`022`](./reference/codes.md#mskittest022) | the explicit endpoint was imported before `MSKit_TestingFramework` was set, the framework changed after it, or no wiring exists for it |
-| [`MSKIT_TEST013`](./reference/codes.md#mskittest013) | a csproj sets `IsTestsProject` directly |
-| [`MSKIT_TEST014`](./reference/codes.md#mskittest014) | a project named like a test project is marked as a helper library |
-| [`MSKIT_TEST025`](./reference/codes.md#mskittest025), [`MSKIT_TEST026`](./reference/codes.md#mskittest026) | a test project has no `MSKit_TestingFramework`, or no installed part wires it |
+| [`MSKITTEST005`](./reference/codes.md#mskittest005) | an xUnit v3 test project targets a framework older than net8.0 |
+| [`MSKITTEST010`](./reference/codes.md#mskittest010)-[`012`](./reference/codes.md#mskittest012), [`MSKITTEST020`](./reference/codes.md#mskittest020)-[`022`](./reference/codes.md#mskittest022) | the explicit endpoint was imported before `MSKit_TestingFramework` was set, the framework changed after it, or no wiring exists for it |
+| [`MSKITTEST013`](./reference/codes.md#mskittest013) | a csproj sets `IsTestsProject` directly |
+| [`MSKITTEST014`](./reference/codes.md#mskittest014) | a project named like a test project is marked as a helper library |
+| [`MSKITTEST025`](./reference/codes.md#mskittest025), [`MSKITTEST026`](./reference/codes.md#mskittest026) | a test project has no `MSKit_TestingFramework`, or no installed part wires it |
diff --git a/docs/troubleshooting.md b/docs/troubleshooting.md
index 83bed30..40134a4 100644
--- a/docs/troubleshooting.md
+++ b/docs/troubleshooting.md
@@ -1,6 +1,6 @@
 # Troubleshooting
 
-Symptoms, their cause, and the fix. A build message with an `MSKIT_` code is explained in the [code reference](./reference/codes.md).
+Symptoms, their cause, and the fix. A kit warning or error code such as `MSKITVER006` is explained in the [code reference](./reference/codes.md), and the code links to its section.
 
 ## Updating
 
@@ -10,18 +10,19 @@ Symptoms, their cause, and the fix. A build message with an `MSKIT_` code is exp
 | `SHA-256 mismatch … expected … (kit.json or --sha256)` | the release zip differs from the one pinned in `kit.json` for the same version | find out why the release changed before installing; `--sha256` with the new hash accepts it |
 | `update.sh` without `--version` installs the version you already have | it reinstalls the pinned version | pass `--version <x.y.z>` ([Install and update](./install-and-update.md)) |
 | `'<Part>' is a default part and cannot be removed` | default parts are always installed | — |
+| After an update, `NoWarn`, `WarningsAsErrors`, `WarningsNotAsErrors` or `MSKit_SkipPackageChecks` no longer affect a kit code | codes lost the underscore after the prefix (`MSKITVER006`) | rename the entries; each section of the [code reference](./reference/codes.md) names the code's former spelling |
 
 ## Building
 
 | Symptom | Cause | Fix |
 | --- | --- | --- |
-| Many [`MSKIT_DUP001`](./reference/codes.md#mskitdup001) errors right after installing | `Directory.Packages.props` repeats versions the kit provides | delete those `PackageVersion` lines, or override the kit's `MSKit_PackageVersion_*` property ([Build](./build.md#central-package-versions)) |
+| Many [`MSKITDUP001`](./reference/codes.md#mskitdup001) errors right after installing | `Directory.Packages.props` repeats versions the kit provides | delete those `PackageVersion` lines, or override the kit's `MSKit_PackageVersion_*` property ([Build](./build.md#central-package-versions)) |
 | The version is `9999.0.0` | a developer-machine build (no `GITHUB_RUN_ID`) | expected; `-p:MSKit_IsDevEnv=False` builds as CI ([Versioning](./versioning.md)) |
-| `dotnet msbuild -getProperty:Version` prints `unknown placeholder: …` | a version template uses a placeholder the engine does not know | fix the template; a real build stops with [`MSKIT_VER002`](./reference/codes.md#mskitver002) |
-| Restore fails on a tag build with [`MSKIT_VER006`](./reference/codes.md#mskitver006) | the tag is not a SemVer 2.0 version | delete the tag and the release, tag again (`v2.1.0`, `v2.1.0-beta.1`) |
-| [`MSKIT_SHARED006`](./reference/codes.md#mskitshared006) / [`007`](./reference/codes.md#mskitshared007) after moving `TargetFrameworks` to `Directory.Build.props` | the csproj still repeats the value | delete it from the csproj |
-| [`MSKIT_SHARED020`](./reference/codes.md#mskitshared020) locally, but CI is green | a csproj changes `TreatWarningsAsErrors`; the check runs on developer machines only | align the csproj, or set `MSKit_SkipAudit_TreatWarningsAsErrors=True` |
-| [`MSKIT_ROSLYN001`](./reference/codes.md#mskitroslyn001)-`003` on a project that is not a Roslyn component | its name ends in `.Analyzers`, `.CodeFixes` or `.SourceGenerator` | rename it, or set `MSKit_Disable<Role>AutoDetect=true` in `Directory.Build.props` above the kit import ([Roslyn](./roslyn.md#wiring-a-project)) |
+| `dotnet msbuild -getProperty:Version` prints `unknown placeholder: …` | a version template uses a placeholder the engine does not know | fix the template; a real build stops with [`MSKITVER002`](./reference/codes.md#mskitver002) |
+| Restore fails on a tag build with [`MSKITVER006`](./reference/codes.md#mskitver006) | the tag is not a SemVer 2.0 version | delete the tag and the release, tag again (`v2.1.0`, `v2.1.0-beta.1`) |
+| [`MSKITSHARED006`](./reference/codes.md#mskitshared006) / [`007`](./reference/codes.md#mskitshared007) after moving `TargetFrameworks` to `Directory.Build.props` | the csproj still repeats the value | delete it from the csproj |
+| [`MSKITSHARED020`](./reference/codes.md#mskitshared020) locally, but CI is green | a csproj changes `TreatWarningsAsErrors`; the check runs on developer machines only | align the csproj, or set `MSKit_SkipAudit_TreatWarningsAsErrors=True` |
+| [`MSKITROSLYN001`](./reference/codes.md#mskitroslyn001)-`003` on a project that is not a Roslyn component | its name ends in `.Analyzers`, `.CodeFixes` or `.SourceGenerator` | rename it, or set `MSKit_Disable<Role>AutoDetect=true` in `Directory.Build.props` above the kit import ([Roslyn](./roslyn.md#wiring-a-project)) |
 | An `*.Analyzers` project builds for the shared target frameworks and references no Roslyn package | the role's props are not imported | add `<Import Project="$(CodeAnalyzerCommonPropsPath)" />` ([Roslyn](./roslyn.md#wiring-a-project)) |
 | `IsNET8` is empty in a csproj `PropertyGroup` of a single-framework project | the constants are known in the props phase only for multi-targeted inner builds | test them in item and target conditions or in `Directory.Build.targets` ([Build](./build.md#target-framework-constants)) |
 
@@ -29,7 +30,7 @@ Symptoms, their cause, and the fix. A build message with an `MSKIT_` code is exp
 
 | Symptom | Cause | Fix |
 | --- | --- | --- |
-| [`MSKIT_TEST013`](./reference/codes.md#mskittest013) | the csproj sets `IsTestsProject` | rename the project to `*.Tests`, or use `$(TestsProjectCommonPropsPath)` ([Testing](./testing.md#which-projects-are-test-projects)) |
+| [`MSKITTEST013`](./reference/codes.md#mskittest013) | the csproj sets `IsTestsProject` | rename the project to `*.Tests`, or use `$(TestsProjectCommonPropsPath)` ([Testing](./testing.md#which-projects-are-test-projects)) |
 | `dotnet test` on SDK 10 rejects `--solution`, `--coverage` or `--report-trx` | without the runner in `global.json` it runs in VSTest mode | add `"test": { "runner": "Microsoft.Testing.Platform" }` ([Microsoft.Testing.Platform mode](https://learn.microsoft.com/dotnet/core/testing/unit-testing-with-dotnet-test)) |
 | NSubstitute cannot mock an internal type | the project under test is not exposing internals | keep `InternalsVisibleToAllTestsProjects` on and the test project under `MSKit_TestsDir` ([Testing](./testing.md#internalsvisibleto)) |
 
@@ -37,6 +38,6 @@ Symptoms, their cause, and the fix. A build message with an `MSKIT_` code is exp
 
 | Symptom | Cause | Fix |
 | --- | --- | --- |
-| `dotnet pack` passes locally and fails on CI with `MSKIT_PKG` errors | the checks are warnings on a developer machine and errors on CI | fix the warnings the local pack prints ([Packaging](./packaging.md#checks)) |
-| [`MSKIT_PKG016`](./reference/codes.md#mskitpkg016) on GitHub Enterprise, GitLab or another host | the release-notes default exists only for `github.com` | set `PackageReleaseNotes`, or generate the readme with `MSKit_PackageReadmeFrom` ([Package readme](./package-readme.md)) |
-| [`MSKIT_PKG021`](./reference/codes.md#mskitpkg021) for every image of a self-hosted GitLab | nuget.org shows images only from its allowed hosts | host the images elsewhere, or point `MSKit_RepoRawUrlTemplate` at an allowed host |
+| `dotnet pack` passes locally and fails on CI with `MSKITPKG` errors | the checks are warnings on a developer machine and errors on CI | fix the warnings the local pack prints ([Packaging](./packaging.md#checks)) |
+| [`MSKITPKG016`](./reference/codes.md#mskitpkg016) on GitHub Enterprise, GitLab or another host | the release-notes default exists only for `github.com` | set `PackageReleaseNotes`, or generate the readme with `MSKit_PackageReadmeFrom` ([Package readme](./package-readme.md)) |
+| [`MSKITPKG021`](./reference/codes.md#mskitpkg021) for every image of a self-hosted GitLab | nuget.org shows images only from its allowed hosts | host the images elsewhere, or point `MSKit_RepoRawUrlTemplate` at an allowed host |
diff --git a/docs/versioning.md b/docs/versioning.md
index a9fc710..330c9be 100644
--- a/docs/versioning.md
+++ b/docs/versioning.md
@@ -14,7 +14,7 @@ With the owner layer's `MSKit_VersionStrategy=ReleaseTag`:
 | A stable branch (`main`, `release/*`), run 7 | `1.4.0-ci.7` | `MSKit_StableVersionTemplate` = `{prefix}-ci.{buildNumber}` |
 | Any other branch, run 7 | `1.4.0-ci.7` | `MSKit_VersionTemplate` = `{prefix}-ci.{buildNumber}` |
 
-A **tag build** is any GitHub Actions run with `GITHUB_REF_TYPE=tag`: publishing a GitHub release creates one, and so does pushing a tag without a release. A leading `v` or `V` is removed; the rest must be [SemVer 2.0](https://semver.org/), or restore fails with [`MSKIT_VER006`](./reference/codes.md#mskitver006). When the tag's `MAJOR.MINOR.PATCH` differs from `VersionPrefix`, [`MSKIT_VER007`](./reference/codes.md#mskitver007) reminds you to bump `VersionPrefix` after the release, so branch builds sort above it.
+A **tag build** is any GitHub Actions run with `GITHUB_REF_TYPE=tag`: publishing a GitHub release creates one, and so does pushing a tag without a release. A leading `v` or `V` is removed; the rest must be [SemVer 2.0](https://semver.org/), or restore fails with [`MSKITVER006`](./reference/codes.md#mskitver006). When the tag's `MAJOR.MINOR.PATCH` differs from `VersionPrefix`, [`MSKITVER007`](./reference/codes.md#mskitver007) reminds you to bump `VersionPrefix` after the release, so branch builds sort above it.
 
 The template is picked in this order: a tag build with `MSKit_ReleaseVersionTemplate` set; a pull-request build with `MSKit_PullRequestVersionTemplate` set; a stable branch (`MSKit_IsStableBranch`, [Build](./build.md#roots-branch-and-commit)) → `MSKit_StableVersionTemplate`; anything else → `MSKit_VersionTemplate`. The version is rendered twice — in the props phase, so `dotnet msbuild -getProperty:Version` answers, and again before compile and pack, so a `VersionPrefix` or template set in a csproj is honoured.
 
@@ -31,7 +31,7 @@ Set `MSKit_VersionStrategy` in `Directory.Build.props`. Any template can be over
 | `VersionTag` | | `{versionTag}` | `{versionTag}` |
 | `Manual` | | the engine is off: set `Version` yourself | |
 
-Only `ReleaseTag` defines release-tag and pull-request templates; with the others a tag or pull-request build uses the branch templates unless you set them. `DateBased` uses the run id modulo 65535 as `{buildNumber}` (never 0). `VersionTag` needs `-p:VersionTag=1.2.3`, else [`MSKIT_VER004`](./reference/codes.md#mskitver004).
+Only `ReleaseTag` defines release-tag and pull-request templates; with the others a tag or pull-request build uses the branch templates unless you set them. `DateBased` uses the run id modulo 65535 as `{buildNumber}` (never 0). `VersionTag` needs `-p:VersionTag=1.2.3`, else [`MSKITVER004`](./reference/codes.md#mskitver004).
 
 ## Placeholders
 
@@ -50,12 +50,12 @@ Only `ReleaseTag` defines release-tag and pull-request templates; with the other
 | `{versionTag}` | `VersionTag` |
 | `{commitShaShort}` | the first 8 characters of `MSKit_CommitSha` |
 
-An unknown placeholder fails the build with [`MSKIT_VER002`](./reference/codes.md#mskitver002). Each project reads the clock on its own; set `MSKit_BuildDateTimeUtc` (property or environment variable) once in CI so every project of one build gets the same date.
+An unknown placeholder fails the build with [`MSKITVER002`](./reference/codes.md#mskitver002). Each project reads the clock on its own; set `MSKit_BuildDateTimeUtc` (property or environment variable) once in CI so every project of one build gets the same date.
 
 ## Setting the version yourself
 
 - **`-p:Version=2.0.0`**, or `Version` set in `Directory.Build.props` above the kit import, always wins: the engine renders nothing (`MSKit_ExplicitVersion`).
-- **`<Version>` in a csproj** fails with [`MSKIT_VER001`](./reference/codes.md#mskitver001) while a template strategy is active, because it would be ignored: declare `VersionPrefix` in `Directory.Version.props`, or set `MSKit_VersionStrategy=Manual`.
+- **`<Version>` in a csproj** fails with [`MSKITVER001`](./reference/codes.md#mskitver001) while a template strategy is active, because it would be ignored: declare `VersionPrefix` in `Directory.Version.props`, or set `MSKit_VersionStrategy=Manual`.
 
 ## CI variables
 
diff --git a/kit/.toolkit/msbuild/DragoAnt.MSBuildKit.Core/audit/audit.autodetect-mutex.targets b/kit/.toolkit/msbuild/DragoAnt.MSBuildKit.Core/audit/audit.autodetect-mutex.targets
index 74fc36e..d0ef456 100644
--- a/kit/.toolkit/msbuild/DragoAnt.MSBuildKit.Core/audit/audit.autodetect-mutex.targets
+++ b/kit/.toolkit/msbuild/DragoAnt.MSBuildKit.Core/audit/audit.autodetect-mutex.targets
@@ -1,13 +1,13 @@
 <Project>
 
-  <!-- MSKIT_CORE001: the project name matched more than one auto-detect regex. -->
+  <!-- MSKITCORE001: the project name matched more than one auto-detect regex. -->
   <Target Name="ValidateAutoDetectedProjectTypeMutex"
           BeforeTargets="CoreCompile;Build"
           Condition="@(MSKit_AutoDetectedProjectType-&gt;Count()) &gt; 1">
     <PropertyGroup>
       <_MSKit_AutoDetectedTypes>@(MSKit_AutoDetectedProjectType, ', ')</_MSKit_AutoDetectedTypes>
     </PropertyGroup>
-    <Error Code="MSKIT_CORE001"
+    <Error Code="MSKITCORE001" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskitcore001"
            File="$(MSBuildProjectFullPath)"
            Text="Project '$(MSBuildProjectName)' auto-detected as MULTIPLE project types: $(_MSKit_AutoDetectedTypes).%0AA project can be exactly ONE type.%0AFix ONE of:%0A  1. Rename the project so its name matches only ONE auto-detect regex%0A  2. Override the conflicting MSKit_*ProjectNameRegex in Directory.Build.props to exclude this project name%0A  3. Set the corresponding MSKit_Disable*AutoDetect=true in the csproj and import the explicit endpoint instead (e.g. MSKit_DisableCodeAnalyzerAutoDetect=true + Import &quot;$(CodeAnalyzerCommonPropsPath)&quot;)" />
   </Target>
diff --git a/kit/.toolkit/msbuild/DragoAnt.MSBuildKit.Core/audit/audit.roslyn-satellites.targets b/kit/.toolkit/msbuild/DragoAnt.MSBuildKit.Core/audit/audit.roslyn-satellites.targets
index d5b0b61..dd97fe2 100644
--- a/kit/.toolkit/msbuild/DragoAnt.MSBuildKit.Core/audit/audit.roslyn-satellites.targets
+++ b/kit/.toolkit/msbuild/DragoAnt.MSBuildKit.Core/audit/audit.roslyn-satellites.targets
@@ -1,13 +1,13 @@
 <Project>
 
-  <!-- MSKIT_ROSLYN001..003: a project name matched a Roslyn auto-detect regex, but the kit part
+  <!-- MSKITROSLYN001..003: a project name matched a Roslyn auto-detect regex, but the kit part
        that wires that project type is not installed. -->
 
   <Target Name="ValidateCodeAnalyzerSatelliteAttached"
           BeforeTargets="CoreCompile;Build"
           Condition="'$(MSKit_IsCodeAnalyzerAutoDetected)'=='True'
                       AND '$(MSKit_CodeAnalyzerSatelliteAttached)'!='true'">
-    <Error Code="MSKIT_ROSLYN001"
+    <Error Code="MSKITROSLYN001" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskitroslyn001"
            File="$(MSBuildProjectFullPath)"
            Text="Project '$(MSBuildProjectName)' name matches the CodeAnalyzer auto-detect regex '$(_MSKit_CodeAnalyzerProjectNameRegex_Shared)' but the kit part 'DragoAnt.MSBuildKit.Project.CodeAnalyzer' is not installed.%0AFix: pwsh .toolkit/update.ps1 -Add Project.CodeAnalyzer   (or: sh .toolkit/update.sh --add Project.CodeAnalyzer)%0AOr, if this project is not a Roslyn analyzer, rename it or set MSKit_DisableCodeAnalyzerAutoDetect=true in the csproj." />
   </Target>
@@ -16,7 +16,7 @@
           BeforeTargets="CoreCompile;Build"
           Condition="'$(MSKit_IsCodeFixerAutoDetected)'=='True'
                       AND '$(MSKit_CodeFixerSatelliteAttached)'!='true'">
-    <Error Code="MSKIT_ROSLYN002"
+    <Error Code="MSKITROSLYN002" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskitroslyn002"
            File="$(MSBuildProjectFullPath)"
            Text="Project '$(MSBuildProjectName)' name matches the CodeFixer auto-detect regex '$(_MSKit_CodeFixerProjectNameRegex_Shared)' but the kit part 'DragoAnt.MSBuildKit.Project.CodeFixer' is not installed.%0AFix: pwsh .toolkit/update.ps1 -Add Project.CodeFixer   (or: sh .toolkit/update.sh --add Project.CodeFixer)%0AOr, if this project is not a Roslyn code-fix provider, rename it or set MSKit_DisableCodeFixerAutoDetect=true in the csproj." />
   </Target>
@@ -25,7 +25,7 @@
           BeforeTargets="CoreCompile;Build"
           Condition="'$(MSKit_IsSourceGeneratorAutoDetected)'=='True'
                       AND '$(MSKit_SourceGeneratorSatelliteAttached)'!='true'">
-    <Error Code="MSKIT_ROSLYN003"
+    <Error Code="MSKITROSLYN003" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskitroslyn003"
            File="$(MSBuildProjectFullPath)"
            Text="Project '$(MSBuildProjectName)' name matches the SourceGenerator auto-detect regex '$(_MSKit_SourceGeneratorProjectNameRegex_Shared)' but the kit part 'DragoAnt.MSBuildKit.Project.SourceGenerator' is not installed.%0AFix: pwsh .toolkit/update.ps1 -Add Project.SourceGenerator   (or: sh .toolkit/update.sh --add Project.SourceGenerator)%0AOr, if this project is not a Roslyn source generator, rename it or set MSKit_DisableSourceGeneratorAutoDetect=true in the csproj." />
   </Target>
diff --git a/kit/.toolkit/msbuild/DragoAnt.MSBuildKit.Core/core.common.props b/kit/.toolkit/msbuild/DragoAnt.MSBuildKit.Core/core.common.props
index cac50d6..f114686 100644
--- a/kit/.toolkit/msbuild/DragoAnt.MSBuildKit.Core/core.common.props
+++ b/kit/.toolkit/msbuild/DragoAnt.MSBuildKit.Core/core.common.props
@@ -2,6 +2,7 @@
 
   <PropertyGroup>
     <MSKit_Diagnostic Condition="'$(MSKit_Diagnostic)'==''">false</MSKit_Diagnostic>
+    <MSKit_CodesHelpBaseUrl Condition="'$(MSKit_CodesHelpBaseUrl)'==''">https://github.com/DragoAnt/MSBuildKit/blob/main/docs/reference/codes.md</MSKit_CodesHelpBaseUrl>
     <!-- True on a developer machine; the Vcs.GitHub part flips it to False on GitHub Actions. -->
     <MSKit_IsDevEnv Condition="'$(MSKit_IsDevEnv)'==''">True</MSKit_IsDevEnv>
 
diff --git a/kit/.toolkit/msbuild/DragoAnt.MSBuildKit.PackageAsProj/packageAsProj.targets b/kit/.toolkit/msbuild/DragoAnt.MSBuildKit.PackageAsProj/packageAsProj.targets
index 03588d0..e90fbe4 100644
--- a/kit/.toolkit/msbuild/DragoAnt.MSBuildKit.PackageAsProj/packageAsProj.targets
+++ b/kit/.toolkit/msbuild/DragoAnt.MSBuildKit.PackageAsProj/packageAsProj.targets
@@ -21,7 +21,7 @@
 
     <Message Text="PackageAsProj: packages attached as ProjectReference instead of PackageReference: @(PackageAsProj_ProjectReference)" Importance="high" />
 
-    <Error Code="MSKIT_PAP001"
+    <Error Code="MSKITPAP001" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskitpap001"
            Condition="'@(PackageAsProj_ProjectReference_Reference)'!=''"
            Text="A package switched to a ProjectReference is still resolved from the package. Fix: run 'dotnet restore --force'."
            File="$(MSBuildProjectFullPath)" />
@@ -33,7 +33,7 @@
       <PackageAsProj_PackageReference_Reference Include="@(PackageAsProj_PackageReference)" Condition="'@(PackageAsProj_PackageReference->'%(Identity)')'=='@(ReferenceAssemblyFilename->'%(Identity)')' And %(Identity)!=''" />
     </ItemGroup>
 
-    <Error Code="MSKIT_PAP002"
+    <Error Code="MSKITPAP002" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskitpap002"
            Condition="'$(PackageAsProj_SkipChecks)'!='True' AND @(PackageAsProj_PackageReference_Reference->Count())!=@(PackageAsProj_PackageReference->Count()) And @(ReferenceAssemblyFilename->Count())!=0"
            Text="A package switched back from a ProjectReference is not restored yet. Fix: run 'dotnet restore --force', or set PackageAsProj_SkipChecks=True to skip this check."
            File="$(MSBuildProjectFullPath)" />
diff --git a/kit/.toolkit/msbuild/DragoAnt.MSBuildKit.Packaging/audit/audit.package.targets b/kit/.toolkit/msbuild/DragoAnt.MSBuildKit.Packaging/audit/audit.package.targets
index fa84441..bf15e43 100644
--- a/kit/.toolkit/msbuild/DragoAnt.MSBuildKit.Packaging/audit/audit.package.targets
+++ b/kit/.toolkit/msbuild/DragoAnt.MSBuildKit.Packaging/audit/audit.package.targets
@@ -1,8 +1,8 @@
 <Project>
 
-  <!-- nuget.org package checks, MSKIT_PKG001..019, run by `dotnet pack`. They are warnings on a
+  <!-- nuget.org package checks, MSKITPKG001..019, run by `dotnet pack`. They are warnings on a
        developer machine and errors on CI (MSKit_PackageChecksAsErrors). Turn single checks off with
-       MSKit_SkipPackageChecks=MSKIT_PKG004;MSKIT_PKG016 (or by listing the code in NoWarn), or all
+       MSKit_SkipPackageChecks=MSKITPKG004;MSKITPKG016 (or by listing the code in NoWarn), or all
        of them with MSKit_SkipPackageChecks=All. -->
 
   <PropertyGroup>
@@ -47,61 +47,61 @@
     </PropertyGroup>
 
     <ItemGroup>
-      <_MSKit_PkgFinding Include="MSKIT_PKG001" Condition="'$(_MSKit_DescriptionIsPlaceholder)'=='True'"
+      <_MSKit_PkgFinding Include="MSKITPKG001" Condition="'$(_MSKit_DescriptionIsPlaceholder)'=='True'"
                          Text="Package '$(PackageId)' has no real Description ('$(_MSKit_Description)'). nuget.org search shows it first: say what the package does and what sets it apart, in one or two sentences."
                          Rule="$(_MSKit_PkgRules)#description" />
-      <_MSKit_PkgFinding Include="MSKIT_PKG002" Condition="'$(_MSKit_DescriptionIsPlaceholder)'!='True' AND $(_MSKit_Description.Length) &lt; $(MSKit_PackageDescriptionMinLength)"
+      <_MSKit_PkgFinding Include="MSKITPKG002" Condition="'$(_MSKit_DescriptionIsPlaceholder)'!='True' AND $(_MSKit_Description.Length) &lt; $(MSKit_PackageDescriptionMinLength)"
                          Text="Package '$(PackageId)' Description is $(_MSKit_Description.Length) characters ('$(_MSKit_Description)'); write at least $(MSKit_PackageDescriptionMinLength): what it does and for whom (MSKit_PackageDescriptionMinLength sets the bar)."
                          Rule="$(_MSKit_PkgRules)#description" />
-      <_MSKit_PkgFinding Include="MSKIT_PKG003" Condition="'$(PackageReadmeFile)'==''"
+      <_MSKit_PkgFinding Include="MSKITPKG003" Condition="'$(PackageReadmeFile)'==''"
                          Text="Package '$(PackageId)' ships no README. Add package.readme.md next to the csproj: what it is, how to start, a short example, where to give feedback."
                          Rule="$(_MSKit_PkgRules)#readme" />
-      <_MSKit_PkgFinding Include="MSKIT_PKG004" Condition="'$(PackageTags)'==''"
+      <_MSKit_PkgFinding Include="MSKITPKG004" Condition="'$(PackageTags)'==''"
                          Text="Package '$(PackageId)' has no PackageTags. Add a few search terms that are not already in the package id."
                          Rule="$(_MSKit_PkgRules)#tags" />
-      <_MSKit_PkgFinding Include="MSKIT_PKG005" Condition="'$(PackageIcon)'==''"
+      <_MSKit_PkgFinding Include="MSKITPKG005" Condition="'$(PackageIcon)'==''"
                          Text="Package '$(PackageId)' has no icon. Set PackageIconPath to a 128x128 PNG or JPEG (the company layer of the kit sets one for every package)."
                          Rule="$(_MSKit_PkgRules)#icon" />
-      <_MSKit_PkgFinding Include="MSKIT_PKG006" Condition="'$(PackageLicenseExpression)'=='' AND '$(PackageLicenseFile)'==''"
+      <_MSKit_PkgFinding Include="MSKITPKG006" Condition="'$(PackageLicenseExpression)'=='' AND '$(PackageLicenseFile)'==''"
                          Text="Package '$(PackageId)' has no licence. Without one nobody may use it. Set PackageLicenseExpression to an SPDX id (for example MIT)."
                          Rule="$(_MSKit_PkgRules)#licensing" />
-      <_MSKit_PkgFinding Include="MSKIT_PKG007" Condition="'$(PackageLicenseUrl)'!=''"
+      <_MSKit_PkgFinding Include="MSKITPKG007" Condition="'$(PackageLicenseUrl)'!=''"
                          Text="Package '$(PackageId)' uses the deprecated PackageLicenseUrl. Replace it with PackageLicenseExpression (an SPDX id) or PackageLicenseFile."
                          Rule="$(_MSKit_PkgRules)#licensing" />
-      <_MSKit_PkgFinding Include="MSKIT_PKG008" Condition="'$(PackageIconUrl)'!=''"
+      <_MSKit_PkgFinding Include="MSKITPKG008" Condition="'$(PackageIconUrl)'!=''"
                          Text="Package '$(PackageId)' uses the deprecated PackageIconUrl. Pack the image and point PackageIcon (or the kit's PackageIconPath) at it."
                          Rule="$(_MSKit_PkgRules)#icon" />
-      <_MSKit_PkgFinding Include="MSKIT_PKG009" Condition="'$(_MSKit_RelativeImages)'!=''"
+      <_MSKit_PkgFinding Include="MSKITPKG009" Condition="'$(_MSKit_RelativeImages)'!=''"
                          Text="The package README of '$(PackageId)' has relative images, which nuget.org does not render: $(_MSKit_RelativeImages). Use absolute https URLs from an allowed host."
                          Rule="$(_MSKit_PkgReadmeRules)#allowed-domains-for-images-and-badges" />
-      <_MSKit_PkgFinding Include="MSKIT_PKG010" Condition="'$(_MSKit_HtmlTags)'!=''"
+      <_MSKit_PkgFinding Include="MSKITPKG010" Condition="'$(_MSKit_HtmlTags)'!=''"
                          Text="The package README of '$(PackageId)' contains HTML, which nuget.org does not render: $(_MSKit_HtmlTags). Use Markdown instead."
                          Rule="$(_MSKit_PkgReadmeRules)#supported-markdown-features" />
-      <_MSKit_PkgFinding Include="MSKIT_PKG011" Condition="'$(_MSKit_Alerts)'!=''"
+      <_MSKit_PkgFinding Include="MSKITPKG011" Condition="'$(_MSKit_Alerts)'!=''"
                          Text="The package README of '$(PackageId)' uses GitHub alert blocks, which nuget.org shows as plain quotes: $(_MSKit_Alerts). Use a bold lead-in such as **Note:** instead."
                          Rule="$(_MSKit_PkgReadmeRules)#supported-markdown-features" />
-      <_MSKit_PkgFinding Include="MSKIT_PKG012" Condition="'$(_MSKit_DisallowedImages)'!=''"
+      <_MSKit_PkgFinding Include="MSKITPKG012" Condition="'$(_MSKit_DisallowedImages)'!=''"
                          Text="The package README of '$(PackageId)' loads images from hosts nuget.org blocks: $(_MSKit_DisallowedImages). Host them on an allowed domain (img.shields.io, raw.githubusercontent.com, ...)."
                          Rule="$(_MSKit_PkgReadmeRules)#allowed-domains-for-images-and-badges" />
-      <_MSKit_PkgFinding Include="MSKIT_PKG013" Condition="'$(_MSKit_PkgVersion)'!='' AND !$([System.Text.RegularExpressions.Regex]::IsMatch('$(_MSKit_PkgVersion)', '$(MSKit_SemVerRegex)'))"
+      <_MSKit_PkgFinding Include="MSKITPKG013" Condition="'$(_MSKit_PkgVersion)'!='' AND !$([System.Text.RegularExpressions.Regex]::IsMatch('$(_MSKit_PkgVersion)', '$(MSKit_SemVerRegex)'))"
                          Text="Package '$(PackageId)' version '$(_MSKit_PkgVersion)' is not SemVer 2.0 (MAJOR.MINOR.PATCH[-prerelease][+metadata])."
                          Rule="$(_MSKit_PkgRules)#package-version" />
-      <_MSKit_PkgFinding Include="MSKIT_PKG014" Condition="'$(_MSKit_RepoUrlFinal)'=='' OR '$(PackageProjectUrl)'==''"
+      <_MSKit_PkgFinding Include="MSKITPKG014" Condition="'$(_MSKit_RepoUrlFinal)'=='' OR '$(PackageProjectUrl)'==''"
                          Text="Package '$(PackageId)' has no repository or project URL. Set RepositoryUrl, or build from a git clone whose origin remote Source Link can read."
                          Rule="$(_MSKit_PkgRules)#repository-type-and-url" />
-      <_MSKit_PkgFinding Include="MSKIT_PKG015" Condition="'$(MSKit_PackageIconSourcePath)'!='' AND Exists('$(MSKit_PackageIconSourcePath)') AND (('$(_MSKit_IconFormat)'!='PNG' AND '$(_MSKit_IconFormat)'!='JPEG') OR '$(_MSKit_IconWidth)'!='$(MSKit_PackageIconSize)' OR '$(_MSKit_IconHeight)'!='$(MSKit_PackageIconSize)')"
+      <_MSKit_PkgFinding Include="MSKITPKG015" Condition="'$(MSKit_PackageIconSourcePath)'!='' AND Exists('$(MSKit_PackageIconSourcePath)') AND (('$(_MSKit_IconFormat)'!='PNG' AND '$(_MSKit_IconFormat)'!='JPEG') OR '$(_MSKit_IconWidth)'!='$(MSKit_PackageIconSize)' OR '$(_MSKit_IconHeight)'!='$(MSKit_PackageIconSize)')"
                          Text="Package '$(PackageId)' icon is not a $(MSKit_PackageIconSize)x$(MSKit_PackageIconSize) PNG or JPEG (format: $(_MSKit_IconFormat), size: $(_MSKit_IconWidth)x$(_MSKit_IconHeight))."
                          Rule="$(_MSKit_PkgRules)#icon" />
-      <_MSKit_PkgFinding Include="MSKIT_PKG016" Condition="'$(PackageReleaseNotes)'==''"
+      <_MSKit_PkgFinding Include="MSKITPKG016" Condition="'$(PackageReleaseNotes)'==''"
                          Text="Package '$(PackageId)' has no PackageReleaseNotes. Set them, or a link to the changelog (the kit links the releases page by default on GitHub, and on any host the generated readme knows with MSKit_PackageReadmeFrom)."
                          Rule="$(_MSKit_PkgRules)#release-notes" />
-      <_MSKit_PkgFinding Include="MSKIT_PKG017" Condition="'$(_MSKit_RelativeLinks)'!=''"
+      <_MSKit_PkgFinding Include="MSKITPKG017" Condition="'$(_MSKit_RelativeLinks)'!=''"
                          Text="The package README of '$(PackageId)' has relative links, which break on nuget.org: $(_MSKit_RelativeLinks). Use absolute URLs."
                          Rule="$(_MSKit_PkgReadmeRules)" />
-      <_MSKit_PkgFinding Include="MSKIT_PKG018" Condition="'$(_MSKit_LicenseIsOpen)'=='True' AND $(Copyright.ToLowerInvariant().Contains('all rights reserved'))"
+      <_MSKit_PkgFinding Include="MSKITPKG018" Condition="'$(_MSKit_LicenseIsOpen)'=='True' AND $(Copyright.ToLowerInvariant().Contains('all rights reserved'))"
                          Text="Package '$(PackageId)' is licensed '$(PackageLicenseExpression)' but its Copyright says 'all rights reserved' ('$(Copyright)'). Use 'Copyright (c) YEAR OWNER'."
                          Rule="$(_MSKit_PkgRules)#copyright" />
-      <_MSKit_PkgFinding Include="MSKIT_PKG019" Condition="'$(_MSKit_HasMermaid)'=='True'"
+      <_MSKit_PkgFinding Include="MSKITPKG019" Condition="'$(_MSKit_HasMermaid)'=='True'"
                          Text="The package README of '$(PackageId)' contains a Mermaid diagram, which nuget.org shows as code. Link to the diagram on GitHub instead."
                          Rule="$(_MSKit_PkgReadmeRules)#supported-markdown-features" />
     </ItemGroup>
@@ -114,11 +114,13 @@
 
     <Warning Condition="'@(_MSKit_PkgFinding)'!='' AND '$(MSKit_PackageChecksAsErrors)'!='True'"
              Code="%(_MSKit_PkgFinding.Identity)"
+             HelpLink="$(MSKit_CodesHelpBaseUrl)#$([System.String]::Copy('%(_MSKit_PkgFinding.Identity)').ToLowerInvariant())"
              Text="%(_MSKit_PkgFinding.Text) Rule: %(_MSKit_PkgFinding.Rule) (to skip: MSKit_SkipPackageChecks=%(_MSKit_PkgFinding.Identity))"
              File="$(MSBuildProjectFullPath)" />
     <Error Condition="'@(_MSKit_PkgFinding)'!='' AND '$(MSKit_PackageChecksAsErrors)'=='True'"
            ContinueOnError="ErrorAndContinue"
            Code="%(_MSKit_PkgFinding.Identity)"
+           HelpLink="$(MSKit_CodesHelpBaseUrl)#$([System.String]::Copy('%(_MSKit_PkgFinding.Identity)').ToLowerInvariant())"
            Text="%(_MSKit_PkgFinding.Text) Rule: %(_MSKit_PkgFinding.Rule) (to skip: MSKit_SkipPackageChecks=%(_MSKit_PkgFinding.Identity))"
            File="$(MSBuildProjectFullPath)" />
   </Target>
diff --git a/kit/.toolkit/msbuild/DragoAnt.MSBuildKit.Packaging/package.inspect.targets b/kit/.toolkit/msbuild/DragoAnt.MSBuildKit.Packaging/package.inspect.targets
index bdb9dd4..061477d 100644
--- a/kit/.toolkit/msbuild/DragoAnt.MSBuildKit.Packaging/package.inspect.targets
+++ b/kit/.toolkit/msbuild/DragoAnt.MSBuildKit.Packaging/package.inspect.targets
@@ -1,6 +1,6 @@
 <Project>
 
-  <!-- Mode="Inspect" reads the package README and icon for the MSKIT_PKG checks; Mode="GenerateReadme"
+  <!-- Mode="Inspect" reads the package README and icon for the MSKITPKG checks; Mode="GenerateReadme"
        writes the readme generated from MSKit_PackageReadmeFrom. The code is in package.tasks.cs.txt. -->
   <UsingTask TaskName="MSKit_PackageAssets"
              TaskFactory="RoslynCodeTaskFactory"
diff --git a/kit/.toolkit/msbuild/DragoAnt.MSBuildKit.Packaging/package.readme.targets b/kit/.toolkit/msbuild/DragoAnt.MSBuildKit.Packaging/package.readme.targets
index 38995aa..228ffa6 100644
--- a/kit/.toolkit/msbuild/DragoAnt.MSBuildKit.Packaging/package.readme.targets
+++ b/kit/.toolkit/msbuild/DragoAnt.MSBuildKit.Packaging/package.readme.targets
@@ -3,7 +3,7 @@
   <!-- MSKit_PackageReadmeFrom: the package readme is generated from the repository README on pack,
        never on build. Relative links and images become absolute URLs pinned to the commit,
        nuget:skip / nuget:only blocks are applied, release and issue links are added to the overview.
-       The MSKIT_PKG checks then read the generated file. Full description: docs/package-readme.md. -->
+       The MSKITPKG checks then read the generated file. Full description: docs/package-readme.md. -->
 
   <PropertyGroup>
     <MSKit_PackageReadmeAllowedImageHostsFile Condition="'$(MSKit_PackageReadmeAllowedImageHostsFile)'==''">$(MSBuildThisFileDirectory)nuget.allowed-image-hosts.txt</MSKit_PackageReadmeAllowedImageHostsFile>
@@ -34,7 +34,7 @@
   <Target Name="_MSKit_PackageReadmeFromMissing"
           BeforeTargets="GenerateNuspec"
           Condition="'$(MSKit_PackageReadmeFrom)'!='' AND '$(_MSKit_GeneratesReadme)'!='True' AND '$(MSKit_SkipPackageChecks)'!='All'">
-    <Warning Code="MSKIT_PKG020" File="$(MSBuildProjectFullPath)"
+    <Warning Code="MSKITPKG020" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskitpkg020" File="$(MSBuildProjectFullPath)"
              Text="MSKit_PackageReadmeFrom names '$(MSKit_PackageReadmeFrom)', but $(_MSKit_ReadmeFromPath) does not exist, so no readme is generated for '$(PackageId)'. The path is relative to the git root ($(MSKit_GitRoot))." />
   </Target>
 
@@ -117,25 +117,25 @@
   <!-- The findings are kept beside the generated file, so an incremental pack still reports them. -->
   <Target Name="_MSKit_ReportPackageReadmeFindings" Condition="'$(MSKit_SkipPackageChecks)'!='All' AND '$(MSKit_SkipPackageChecks)'!='True'">
     <ItemGroup>
-      <_MSKit_ReadmeCode Include="MSKIT_PKG020;MSKIT_PKG021;MSKIT_PKG022" />
+      <_MSKit_ReadmeCode Include="MSKITPKG020;MSKITPKG021;MSKITPKG022" />
       <_MSKit_ReadmeSkip Include="$(MSKit_SkipPackageChecks);$(NoWarn)" />
       <_MSKit_ReadmeCode Remove="@(_MSKit_ReadmeSkip)" />
     </ItemGroup>
     <PropertyGroup>
       <_MSKit_ReadmeCodes>;@(_MSKit_ReadmeCode);</_MSKit_ReadmeCodes>
     </PropertyGroup>
-    <ReadLinesFromFile Condition="Exists('$(_MSKit_ReadmeFindingsBase).MSKIT_PKG020.txt') AND $(_MSKit_ReadmeCodes.Contains(';MSKIT_PKG020;'))" File="$(_MSKit_ReadmeFindingsBase).MSKIT_PKG020.txt">
+    <ReadLinesFromFile Condition="Exists('$(_MSKit_ReadmeFindingsBase).MSKITPKG020.txt') AND $(_MSKit_ReadmeCodes.Contains(';MSKITPKG020;'))" File="$(_MSKit_ReadmeFindingsBase).MSKITPKG020.txt">
       <Output TaskParameter="Lines" ItemName="_MSKit_ReadmeFinding020" />
     </ReadLinesFromFile>
-    <ReadLinesFromFile Condition="Exists('$(_MSKit_ReadmeFindingsBase).MSKIT_PKG021.txt') AND $(_MSKit_ReadmeCodes.Contains(';MSKIT_PKG021;'))" File="$(_MSKit_ReadmeFindingsBase).MSKIT_PKG021.txt">
+    <ReadLinesFromFile Condition="Exists('$(_MSKit_ReadmeFindingsBase).MSKITPKG021.txt') AND $(_MSKit_ReadmeCodes.Contains(';MSKITPKG021;'))" File="$(_MSKit_ReadmeFindingsBase).MSKITPKG021.txt">
       <Output TaskParameter="Lines" ItemName="_MSKit_ReadmeFinding021" />
     </ReadLinesFromFile>
-    <ReadLinesFromFile Condition="Exists('$(_MSKit_ReadmeFindingsBase).MSKIT_PKG022.txt') AND $(_MSKit_ReadmeCodes.Contains(';MSKIT_PKG022;'))" File="$(_MSKit_ReadmeFindingsBase).MSKIT_PKG022.txt">
+    <ReadLinesFromFile Condition="Exists('$(_MSKit_ReadmeFindingsBase).MSKITPKG022.txt') AND $(_MSKit_ReadmeCodes.Contains(';MSKITPKG022;'))" File="$(_MSKit_ReadmeFindingsBase).MSKITPKG022.txt">
       <Output TaskParameter="Lines" ItemName="_MSKit_ReadmeFinding022" />
     </ReadLinesFromFile>
-    <Warning Condition="'@(_MSKit_ReadmeFinding020)'!=''" Code="MSKIT_PKG020" File="$(_MSKit_ReadmeFromPath)" Text="%(_MSKit_ReadmeFinding020.Identity) (to skip: MSKit_SkipPackageChecks=MSKIT_PKG020)" />
-    <Warning Condition="'@(_MSKit_ReadmeFinding021)'!=''" Code="MSKIT_PKG021" File="$(_MSKit_ReadmeFromPath)" Text="%(_MSKit_ReadmeFinding021.Identity) (to skip: MSKit_SkipPackageChecks=MSKIT_PKG021)" />
-    <Warning Condition="'@(_MSKit_ReadmeFinding022)'!=''" Code="MSKIT_PKG022" File="$(_MSKit_ReadmeFromPath)" Text="%(_MSKit_ReadmeFinding022.Identity) (to skip: MSKit_SkipPackageChecks=MSKIT_PKG022)" />
+    <Warning Condition="'@(_MSKit_ReadmeFinding020)'!=''" Code="MSKITPKG020" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskitpkg020" File="$(_MSKit_ReadmeFromPath)" Text="%(_MSKit_ReadmeFinding020.Identity) (to skip: MSKit_SkipPackageChecks=MSKITPKG020)" />
+    <Warning Condition="'@(_MSKit_ReadmeFinding021)'!=''" Code="MSKITPKG021" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskitpkg021" File="$(_MSKit_ReadmeFromPath)" Text="%(_MSKit_ReadmeFinding021.Identity) (to skip: MSKit_SkipPackageChecks=MSKITPKG021)" />
+    <Warning Condition="'@(_MSKit_ReadmeFinding022)'!=''" Code="MSKITPKG022" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskitpkg022" File="$(_MSKit_ReadmeFromPath)" Text="%(_MSKit_ReadmeFinding022.Identity) (to skip: MSKit_SkipPackageChecks=MSKITPKG022)" />
   </Target>
 
 </Project>
diff --git a/kit/.toolkit/msbuild/DragoAnt.MSBuildKit.Packaging/package.tasks.cs.txt b/kit/.toolkit/msbuild/DragoAnt.MSBuildKit.Packaging/package.tasks.cs.txt
index 0ef49d8..4d3b6d5 100644
--- a/kit/.toolkit/msbuild/DragoAnt.MSBuildKit.Packaging/package.tasks.cs.txt
+++ b/kit/.toolkit/msbuild/DragoAnt.MSBuildKit.Packaging/package.tasks.cs.txt
@@ -165,7 +165,7 @@ public sealed class MSKit_PackageAssets : Task
 
     private void GenerateReadme()
     {
-        var codes =new[] { "MSKIT_PKG020", "MSKIT_PKG021", "MSKIT_PKG022" };
+        var codes =new[] { "MSKITPKG020", "MSKITPKG021", "MSKITPKG022" };
         var findings = codes.ToDictionary(c => c, c => new List<string>());
         Action<string, string> report = (code, text) => findings[code].Add(text.Replace("\r", " ").Replace("\n", " "));
 
@@ -238,7 +238,7 @@ public sealed class MSKit_PackageAssets : Task
             case "":
                 break;
             default:
-                report("MSKIT_PKG020", display + ": MSKit_RepoProvider '" + provider + "' is not one of GitHub, GitLab, AzureDevOps, Bitbucket, Gitea; set MSKit_RepoBlobUrlTemplate and MSKit_RepoRawUrlTemplate instead.");
+                report("MSKITPKG020", display + ": MSKit_RepoProvider '" + provider + "' is not one of GitHub, GitLab, AzureDevOps, Bitbucket, Gitea; set MSKit_RepoBlobUrlTemplate and MSKit_RepoRawUrlTemplate instead.");
                 break;
         }
         if (norm(BlobTemplate).Length > 0) { blob = norm(BlobTemplate); tree = blob.Contains("/blob/") ? blob.Replace("/blob/", "/tree/") : blob; }
@@ -277,7 +277,7 @@ public sealed class MSKit_PackageAssets : Task
             if (!Uri.TryCreate(url.Trim('<', '>'), UriKind.Absolute, out u) || (u.Scheme != "https" && u.Scheme != "http")) return;
             var h = u.Host.ToLowerInvariant();
             if (allowed.Contains(h) || (h == "github.com" && Regex.IsMatch(u.AbsolutePath, @"^/[^/]+/[^/]+/(actions/)?workflows/[^/]+/badge\.svg$", RegexOptions.IgnoreCase))) return;
-            report("MSKIT_PKG021", display + " line " + n + ": the image " + url + " comes from " + h + ", a host nuget.org does not show images from. Use an allowed host (nuget.allowed-image-hosts.txt in the kit) or point MSKit_RepoRawUrlTemplate at one.");
+            report("MSKITPKG021", display + " line " + n + ": the image " + url + " comes from " + h + ", a host nuget.org does not show images from. Use an allowed host (nuget.allowed-image-hosts.txt in the kit) or point MSKit_RepoRawUrlTemplate at one.");
         };
 
         Func<string, bool, int, string> resolve = (target, isImage, n) =>
@@ -293,7 +293,7 @@ public sealed class MSKit_PackageAssets : Task
             var rp = combine(Uri.UnescapeDataString(p));
             if (rp == null)
             {
-                report("MSKIT_PKG020", display + " line " + n + ": " + t + " points outside the repository and is left as it is.");
+                report("MSKITPKG020", display + " line " + n + ": " + t + " points outside the repository and is left as it is.");
                 return target;
             }
             var isDir = Directory.Exists(Path.Combine(root, rp.Replace('/', Path.DirectorySeparatorChar)));
@@ -361,25 +361,25 @@ public sealed class MSKit_PackageAssets : Task
             }
             if (skipOpen.IsMatch(line))
             {
-                if (skipping) report("MSKIT_PKG020", display + " line " + n + ": nuget:skip opened again before line " + skipLine + "'s was closed.");
+                if (skipping) report("MSKITPKG020", display + " line " + n + ": nuget:skip opened again before line " + skipLine + "'s was closed.");
                 skipping = true; skipLine = n; continue;
             }
             if (skipClose.IsMatch(line))
             {
-                if (!skipping) report("MSKIT_PKG020", display + " line " + n + ": /nuget:skip has no matching nuget:skip.");
+                if (!skipping) report("MSKITPKG020", display + " line " + n + ": /nuget:skip has no matching nuget:skip.");
                 skipping = false; continue;
             }
             var om = onlyOpen.Match(line);
             if (om.Success)
             {
-                if (inOnly) report("MSKIT_PKG020", display + " line " + n + ": nuget:only opened again before line " + onlyLine + "'s was closed.");
+                if (inOnly) report("MSKITPKG020", display + " line " + n + ": nuget:only opened again before line " + onlyLine + "'s was closed.");
                 inOnly = true; onlyLine = n;
                 keepOnly = Regex.Split(om.Groups[1].Value.Trim(), @"[\s,]+").Any(id => string.Equals(id, PackageId, StringComparison.OrdinalIgnoreCase));
                 continue;
             }
             if (onlyClose.IsMatch(line))
             {
-                if (!inOnly) report("MSKIT_PKG020", display + " line " + n + ": /nuget:only has no matching nuget:only.");
+                if (!inOnly) report("MSKITPKG020", display + " line " + n + ": /nuget:only has no matching nuget:only.");
                 inOnly = false; keepOnly = true; continue;
             }
             var fm = fenceRe.Match(line);
@@ -393,10 +393,10 @@ public sealed class MSKit_PackageAssets : Task
             outLines.Add(rewriteLine(line, n));
             outFence.Add(false);
         }
-        if (skipping) report("MSKIT_PKG020", display + " line " + skipLine + ": nuget:skip is never closed, so everything after it is left out.");
-        if (inOnly) report("MSKIT_PKG020", display + " line " + onlyLine + ": nuget:only is never closed.");
+        if (skipping) report("MSKITPKG020", display + " line " + skipLine + ": nuget:skip is never closed, so everything after it is left out.");
+        if (inOnly) report("MSKITPKG020", display + " line " + onlyLine + ": nuget:only is never closed.");
         if (!canRewrite && unresolved > 0)
-            report("MSKIT_PKG020", display + ": " + unresolved + " relative link(s) and image(s) stay relative because " + why + ".");
+            report("MSKITPKG020", display + ": " + unresolved + " relative link(s) and image(s) stay relative because " + why + ".");
 
         var title = norm(ReadmeTitle) == "auto" ? norm(PackageId) : norm(ReadmeTitle);
         if (title.Length > 0)
@@ -449,7 +449,7 @@ public sealed class MSKit_PackageAssets : Task
 
         var visibility = norm(Visibility).ToLowerInvariant();
         if (visibility == "private" || visibility == "internal")
-            report("MSKIT_PKG022", "The repository " + (repoUrl.Length > 0 ? repoUrl : "of " + PackageId) + " is " + visibility + ": the links in the package readme of " + PackageId + " will not open for people reading it on nuget.org. Publish from a public repository, or point MSKit_RepoBlobUrlTemplate and MSKit_RepoRawUrlTemplate at a public mirror.");
+            report("MSKITPKG022", "The repository " + (repoUrl.Length > 0 ? repoUrl : "of " + PackageId) + " is " + visibility + ": the links in the package readme of " + PackageId + " will not open for people reading it on nuget.org. Publish from a public repository, or point MSKit_RepoBlobUrlTemplate and MSKit_RepoRawUrlTemplate at a public mirror.");
 
         var result = new List<string>();
         var blank = true;
diff --git a/kit/.toolkit/msbuild/DragoAnt.MSBuildKit.Testing.XUnit.v3/audit/audit.tests.project.xunit.v3.targets b/kit/.toolkit/msbuild/DragoAnt.MSBuildKit.Testing.XUnit.v3/audit/audit.tests.project.xunit.v3.targets
index febe8d5..adb4177 100644
--- a/kit/.toolkit/msbuild/DragoAnt.MSBuildKit.Testing.XUnit.v3/audit/audit.tests.project.xunit.v3.targets
+++ b/kit/.toolkit/msbuild/DragoAnt.MSBuildKit.Testing.XUnit.v3/audit/audit.tests.project.xunit.v3.targets
@@ -1,13 +1,13 @@
 <Project>
 
-  <!-- MSKIT_TEST005: xunit.v3 needs net8.0 or later. -->
+  <!-- MSKITTEST005: xunit.v3 needs net8.0 or later. -->
   <Target Name="ValidateXUnitV3TFM"
           BeforeTargets="Build"
           Condition="'$(IsTestsProject)'=='True'
                       AND '$(MSKit_TestingFramework)'=='xunit.v3'
                       AND '$(TargetFramework)'!=''
                       AND '$(IsNET8_OR_GREATER)'!='True'">
-    <Error Code="MSKIT_TEST005"
+    <Error Code="MSKITTEST005" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskittest005"
            File="$(MSBuildProjectFullPath)"
            Text="MSKit_TestingFramework='xunit.v3' requires net8.0 or later. Current target framework: $(TargetFramework).%0AFix: target net8.0 or later in the test project." />
   </Target>
diff --git a/kit/.toolkit/msbuild/DragoAnt.MSBuildKit.Testing/audit/audit.internalsVisibleTo.targets b/kit/.toolkit/msbuild/DragoAnt.MSBuildKit.Testing/audit/audit.internalsVisibleTo.targets
index 8de8fe0..3164d5b 100644
--- a/kit/.toolkit/msbuild/DragoAnt.MSBuildKit.Testing/audit/audit.internalsVisibleTo.targets
+++ b/kit/.toolkit/msbuild/DragoAnt.MSBuildKit.Testing/audit/audit.internalsVisibleTo.targets
@@ -4,7 +4,7 @@
 
   <!-- Gated like test.project.internalsVisibleTo.targets: only non-test projects emit InternalsVisibleTo. -->
   <Target Name="ValidateMSKitTestsDirSet" BeforeTargets="BeforeCompile" Condition="'$(InternalsVisibleToAllTestsProjects)'=='True'">
-    <Warning Code="MSKIT_TEST030" Condition="'$(MSKit_TestsDir)'==''"
+    <Warning Code="MSKITTEST030" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskittest030" Condition="'$(MSKit_TestsDir)'==''"
              Text="MSKit_TestsDir is empty — cannot auto-emit InternalsVisibleTo for sibling .Tests projects.%0AFix: set MSKit_TestsDir in Directory.Build.props:%0A  &lt;PropertyGroup&gt;%0A    &lt;MSKit_TestsDir&gt;$(MSBuildThisFileDirectory)tests&lt;/MSKit_TestsDir&gt;%0A  &lt;/PropertyGroup&gt;%0ATo disable auto InternalsVisibleTo, add to csproj:%0A  &lt;PropertyGroup&gt;%0A    &lt;InternalsVisibleToAllTestsProjects&gt;False&lt;/InternalsVisibleToAllTestsProjects&gt;%0A  &lt;/PropertyGroup&gt;"
              File="$(MSBuildProjectFullPath)" />
   </Target>
@@ -12,7 +12,7 @@
   <!-- Warn when MSKit_TestsDir points to a non-existent directory.
        Gate: InternalsVisibleToAllTestsProjects==True — see ValidateMSKitTestsDirSet for rationale. -->
   <Target Name="ValidateMSKitTestsDirExists" BeforeTargets="BeforeCompile" Condition="'$(InternalsVisibleToAllTestsProjects)'=='True'">
-    <Warning Code="MSKIT_TEST031" Condition="'$(MSKit_TestsDir)'!='' And !Exists('$(MSKit_TestsDir)')"
+    <Warning Code="MSKITTEST031" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskittest031" Condition="'$(MSKit_TestsDir)'!='' And !Exists('$(MSKit_TestsDir)')"
              Text="MSKit_TestsDir='$(MSKit_TestsDir)' does not exist.%0AFix: point MSKit_TestsDir to an existing directory in Directory.Build.props:%0A  &lt;PropertyGroup&gt;%0A    &lt;MSKit_TestsDir&gt;$(MSBuildThisFileDirectory)tests&lt;/MSKit_TestsDir&gt;%0A  &lt;/PropertyGroup&gt;%0ATo disable auto InternalsVisibleTo, add to csproj:%0A  &lt;PropertyGroup&gt;%0A    &lt;InternalsVisibleToAllTestsProjects&gt;False&lt;/InternalsVisibleToAllTestsProjects&gt;%0A  &lt;/PropertyGroup&gt;"
              File="$(MSBuildProjectFullPath)" />
   </Target>
diff --git a/kit/.toolkit/msbuild/DragoAnt.MSBuildKit.Testing/audit/audit.tests.lib.project.targets b/kit/.toolkit/msbuild/DragoAnt.MSBuildKit.Testing/audit/audit.tests.lib.project.targets
index 11cb07e..0d8e18e 100644
--- a/kit/.toolkit/msbuild/DragoAnt.MSBuildKit.Testing/audit/audit.tests.lib.project.targets
+++ b/kit/.toolkit/msbuild/DragoAnt.MSBuildKit.Testing/audit/audit.tests.lib.project.targets
@@ -1,35 +1,35 @@
 <Project>
 
-  <!-- Test helper library checks, MSKIT_TEST020..022. A test helper library may also set IsTestsLibProject directly: everything it needs is wired in the targets phase. -->
+  <!-- Test helper library checks, MSKITTEST020..022. A test helper library may also set IsTestsLibProject directly: everything it needs is wired in the targets phase. -->
 
-  <!-- MSKIT_TEST020: MSKit_TestingFramework must be set BEFORE LibCommonProps Import -->
+  <!-- MSKITTEST020: MSKit_TestingFramework must be set BEFORE LibCommonProps Import -->
   <Target Name="ValidateTestingFrameworkSetBeforeLibCommonPropsImport"
           BeforeTargets="CoreCompile;Build"
           Condition="'$(_MSKit_TestsLibProjectCommonPropsImported)'=='True'
                       AND '$(_MSKit_TestingFrameworkAtLibCommonPropsImport)'==''">
-    <Error Code="MSKIT_TEST020"
+    <Error Code="MSKITTEST020" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskittest020"
            File="$(MSBuildProjectFullPath)"
            Text="MSKit_TestingFramework was not set when $(TestsLibProjectCommonPropsPath) was imported.%0AFix: set the framework PropertyGroup BEFORE the Import:%0A  &lt;PropertyGroup&gt;%0A    &lt;MSKit_TestingFramework&gt;xunit.v3&lt;/MSKit_TestingFramework&gt;%0A  &lt;/PropertyGroup&gt;%0A  &lt;Import Project=&quot;$(TestsLibProjectCommonPropsPath)&quot; /&gt;" />
   </Target>
 
-  <!-- MSKIT_TEST021: framework changed after the Lib Import -->
+  <!-- MSKITTEST021: framework changed after the Lib Import -->
   <Target Name="ValidateTestingFrameworkUnchangedSinceLibImport"
           BeforeTargets="CoreCompile;Build"
           Condition="'$(_MSKit_TestsLibProjectCommonPropsImported)'=='True'
                       AND '$(_MSKit_TestingFrameworkAtLibCommonPropsImport)'!=''
                       AND '$(_MSKit_TestingFrameworkAtLibCommonPropsImport)'!='$(MSKit_TestingFramework)'">
-    <Error Code="MSKIT_TEST021"
+    <Error Code="MSKITTEST021" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskittest021"
            File="$(MSBuildProjectFullPath)"
            Text="MSKit_TestingFramework changed after $(TestsLibProjectCommonPropsPath) was imported.%0AAt import: '$(_MSKit_TestingFrameworkAtLibCommonPropsImport)'   csproj-final: '$(MSKit_TestingFramework)'.%0AFix: move the framework PropertyGroup ABOVE the Import." />
   </Target>
 
-  <!-- MSKIT_TEST022: no satellite or custom LibCommonProps path resolved -->
+  <!-- MSKITTEST022: no satellite or custom LibCommonProps path resolved -->
   <Target Name="ValidateTestingFrameworkLibCommonPropsPathResolved"
           BeforeTargets="CoreCompile;Build"
           Condition="'$(_MSKit_TestsLibProjectCommonPropsImported)'=='True'
                       AND '$(MSKit_TestingFramework_LibCommonPropsPath)'==''
                       AND '$(MSKit_TestingFramework)'!=''">
-    <Error Code="MSKIT_TEST022"
+    <Error Code="MSKITTEST022" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskittest022"
            File="$(MSBuildProjectFullPath)"
            Text="No LibCommonProps path resolved for MSKit_TestingFramework='$(MSKit_TestingFramework)'.%0AFix: use a framework the kit ships (xunit.v3) or set MSKit_TestingFramework_LibCommonPropsPath to a custom file." />
   </Target>
diff --git a/kit/.toolkit/msbuild/DragoAnt.MSBuildKit.Testing/audit/audit.tests.project.targets b/kit/.toolkit/msbuild/DragoAnt.MSBuildKit.Testing/audit/audit.tests.project.targets
index 8075de2..5035f83 100644
--- a/kit/.toolkit/msbuild/DragoAnt.MSBuildKit.Testing/audit/audit.tests.project.targets
+++ b/kit/.toolkit/msbuild/DragoAnt.MSBuildKit.Testing/audit/audit.tests.project.targets
@@ -1,13 +1,13 @@
 <Project>
 
-  <!-- Runnable-test-project checks, MSKIT_TEST010..026. BeforeTargets includes CoreCompile so they
+  <!-- Runnable-test-project checks, MSKITTEST010..026. BeforeTargets includes CoreCompile so they
        fire before generated entry-point code can mask them with compiler errors. -->
 
   <Target Name="ValidateTestingFrameworkSetBeforeCommonPropsImport"
           BeforeTargets="CoreCompile;Build"
           Condition="'$(_MSKit_TestsProjectCommonPropsImported)'=='True'
                       AND '$(_MSKit_TestingFrameworkAtCommonPropsImport)'==''">
-    <Error Code="MSKIT_TEST010"
+    <Error Code="MSKITTEST010" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskittest010"
            File="$(MSBuildProjectFullPath)"
            Text="MSKit_TestingFramework was not set when $(TestsProjectCommonPropsPath) was imported.%0AFix: set it BEFORE the Import:%0A  &lt;PropertyGroup&gt;%0A    &lt;MSKit_TestingFramework&gt;xunit.v3&lt;/MSKit_TestingFramework&gt;%0A  &lt;/PropertyGroup&gt;%0A  &lt;Import Project=&quot;$(TestsProjectCommonPropsPath)&quot; /&gt;" />
   </Target>
@@ -17,7 +17,7 @@
           Condition="'$(_MSKit_TestsProjectCommonPropsImported)'=='True'
                       AND '$(_MSKit_TestingFrameworkAtCommonPropsImport)'!=''
                       AND '$(_MSKit_TestingFrameworkAtCommonPropsImport)'!='$(MSKit_TestingFramework)'">
-    <Error Code="MSKIT_TEST011"
+    <Error Code="MSKITTEST011" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskittest011"
            File="$(MSBuildProjectFullPath)"
            Text="MSKit_TestingFramework changed after $(TestsProjectCommonPropsPath) was imported (at import: '$(_MSKit_TestingFrameworkAtCommonPropsImport)', final: '$(MSKit_TestingFramework)').%0AFix: move the framework PropertyGroup above the Import." />
   </Target>
@@ -27,12 +27,12 @@
           Condition="'$(_MSKit_TestsProjectCommonPropsImported)'=='True'
                       AND '$(MSKit_TestingFramework_CommonPropsPath)'==''
                       AND '$(MSKit_TestingFramework)'!=''">
-    <Error Code="MSKIT_TEST012"
+    <Error Code="MSKITTEST012" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskittest012"
            File="$(MSBuildProjectFullPath)"
            Text="No framework wiring found for MSKit_TestingFramework='$(MSKit_TestingFramework)'.%0AFix: use a framework the kit ships (xunit.v3), or point MSKit_TestingFramework_CommonPropsPath at your own props file." />
   </Target>
 
-  <!-- MSKIT_TEST013 reads the csproj text, comments stripped, so a direct declaration is caught
+  <!-- MSKITTEST013 reads the csproj text, comments stripped, so a direct declaration is caught
        even when the name would also match auto-detect. -->
   <Target Name="ValidateIsTestsProjectNotSetDirectly"
           BeforeTargets="CoreCompile;Build"
@@ -44,7 +44,7 @@
       <_MSKit_CsprojText013>$([System.Text.RegularExpressions.Regex]::Replace($(_MSKit_CsprojText013), '&lt;!--[\s\S]*?--&gt;', ''))</_MSKit_CsprojText013>
       <_MSKit_HasDirectIsTestsProject>$([System.Text.RegularExpressions.Regex]::IsMatch($(_MSKit_CsprojText013), '&lt;IsTestsProject\s*&gt;'))</_MSKit_HasDirectIsTestsProject>
     </PropertyGroup>
-    <Error Code="MSKIT_TEST013"
+    <Error Code="MSKITTEST013" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskittest013"
            File="$(MSBuildProjectFullPath)"
            Condition="'$(_MSKit_HasDirectIsTestsProject)'=='True'"
            Text="csproj '$(MSBuildProjectName)' declares &lt;IsTestsProject&gt; directly. That is set too late for the Microsoft.Testing.Platform wiring, which happens in the props phase.%0AFix: rename the project to match MSKit_TestsProjectNameRegex (default: names ending in .Tests), or replace the property with the explicit endpoint:%0A  &lt;PropertyGroup&gt;%0A    &lt;MSKit_TestingFramework&gt;xunit.v3&lt;/MSKit_TestingFramework&gt;%0A  &lt;/PropertyGroup&gt;%0A  &lt;Import Project=&quot;$(TestsProjectCommonPropsPath)&quot; /&gt;" />
@@ -55,7 +55,7 @@
           Condition="'$(MSKit_IsTestsProjectAutoDetected)'=='True'
                       AND ('$(IsTestsLibProject)'=='True' OR '$(_MSKit_TestsLibProjectCommonPropsImported)'=='True')
                       AND '$(MSKit_IsTestsLibProjectAutoDetected)'!='True'">
-    <Error Code="MSKIT_TEST014"
+    <Error Code="MSKITTEST014" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskittest014"
            File="$(MSBuildProjectFullPath)"
            Text="Project name '$(MSBuildProjectName)' matches the tests auto-detect regex '$(_MSKit_TestsProjectNameRegex_Shared)' but the project is marked as a test helper library. A project cannot be both.%0AFix one of:%0A  1. Rename the project so it no longer matches (e.g. 'Foo.Tests' to 'Foo.TestUtils')%0A  2. Override MSKit_TestsProjectNameRegex in Directory.Build.props%0A  3. Drop the IsTestsLibProject flag if this is a runnable test project" />
   </Target>
@@ -65,7 +65,7 @@
           Condition="('$(IsTestsProject)'=='True' OR '$(IsTestsLibProject)'=='True')
                       AND '$(MSKit_TestingFramework)'!=''
                       AND '$(MSKit_TestingFrameworkAttached)'!='true'">
-    <Error Code="MSKIT_TEST026"
+    <Error Code="MSKITTEST026" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskittest026"
            File="$(MSBuildProjectFullPath)"
            Text="Project '$(MSBuildProjectName)' has MSKit_TestingFramework='$(MSKit_TestingFramework)' but no installed kit part wires that framework.%0AFix: use xunit.v3 (part DragoAnt.MSBuildKit.Testing.XUnit.v3), or set MSKit_TestingFramework_CommonPropsPath to your own wiring." />
   </Target>
@@ -74,7 +74,7 @@
           BeforeTargets="CoreCompile;Build"
           Condition="('$(IsTestsProject)'=='True' OR '$(IsTestsLibProject)'=='True')
                       AND '$(MSKit_TestingFramework)'==''">
-    <Error Code="MSKIT_TEST025"
+    <Error Code="MSKITTEST025" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskittest025"
            File="$(MSBuildProjectFullPath)"
            Text="Project '$(MSBuildProjectName)' is a test project but MSKit_TestingFramework is not set.%0AFix: add to Directory.Build.props:%0A  &lt;MSKit_TestingFramework&gt;xunit.v3&lt;/MSKit_TestingFramework&gt;" />
   </Target>
diff --git a/kit/.toolkit/msbuild/DragoAnt.MSBuildKit.Testing/tests.lib.project.common.props b/kit/.toolkit/msbuild/DragoAnt.MSBuildKit.Testing/tests.lib.project.common.props
index 9685d6b..e280c2f 100644
--- a/kit/.toolkit/msbuild/DragoAnt.MSBuildKit.Testing/tests.lib.project.common.props
+++ b/kit/.toolkit/msbuild/DragoAnt.MSBuildKit.Testing/tests.lib.project.common.props
@@ -1,7 +1,7 @@
 <Project>
 
   <!-- Explicit endpoint for a test helper library. Set MSKit_TestingFramework before the import
-       (MSKIT_TEST020 checks it). -->
+       (MSKITTEST020 checks it). -->
   <PropertyGroup>
     <_MSKit_TestingFrameworkAtLibCommonPropsImport>$(MSKit_TestingFramework)</_MSKit_TestingFrameworkAtLibCommonPropsImport>
     <_MSKit_TestsLibProjectCommonPropsImported>True</_MSKit_TestsLibProjectCommonPropsImported>
diff --git a/kit/.toolkit/msbuild/DragoAnt.MSBuildKit.Testing/tests.project.common.props b/kit/.toolkit/msbuild/DragoAnt.MSBuildKit.Testing/tests.project.common.props
index 72b358c..bc9dfbb 100644
--- a/kit/.toolkit/msbuild/DragoAnt.MSBuildKit.Testing/tests.project.common.props
+++ b/kit/.toolkit/msbuild/DragoAnt.MSBuildKit.Testing/tests.project.common.props
@@ -1,7 +1,7 @@
 <Project>
 
   <!-- Explicit endpoint for a runnable test project whose name the auto-detect regex does not
-       match. Set MSKit_TestingFramework before the import (MSKIT_TEST010 checks it). -->
+       match. Set MSKit_TestingFramework before the import (MSKITTEST010 checks it). -->
   <PropertyGroup>
     <_MSKit_TestingFrameworkAtCommonPropsImport>$(MSKit_TestingFramework)</_MSKit_TestingFrameworkAtCommonPropsImport>
     <_MSKit_TestsProjectCommonPropsImported>True</_MSKit_TestsProjectCommonPropsImported>
diff --git a/kit/.toolkit/msbuild/DragoAnt.MSBuildKit/audit/audit.implicit.packages.duplicates.targets b/kit/.toolkit/msbuild/DragoAnt.MSBuildKit/audit/audit.implicit.packages.duplicates.targets
index b03a750..225b9e6 100644
--- a/kit/.toolkit/msbuild/DragoAnt.MSBuildKit/audit/audit.implicit.packages.duplicates.targets
+++ b/kit/.toolkit/msbuild/DragoAnt.MSBuildKit/audit/audit.implicit.packages.duplicates.targets
@@ -1,6 +1,6 @@
 <Project>
 
-  <!-- MSKIT_DUP001: Directory.Packages.props declares a <PackageVersion> the kit already declares
+  <!-- MSKITDUP001: Directory.Packages.props declares a <PackageVersion> the kit already declares
        (the kit's items carry ControlledBy metadata). NuGet would otherwise report NU1506 and pick
        one silently. MSKit_SkipAudit_ImplicitPackageDuplicates=True bypasses the check. -->
 
@@ -25,7 +25,7 @@
                                          AND $(_MSKit_ConsumerIdsStr.Contains(';%(PackageVersion.Identity);'))" />
     </ItemGroup>
 
-    <Error Code="MSKIT_DUP001"
+    <Error Code="MSKITDUP001" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskitdup001"
            Condition=" '@(_MSKit_DuplicateReport)' != '' "
            Text="Directory.Packages.props declares &lt;PackageVersion&gt; entries the kit already provides:%0A%0A@(_MSKit_DuplicateReport->'  %(Identity)  &#x2190; provided by %(ControlledBy)','%0A')%0A%0AFix: remove those &lt;PackageVersion Include=&quot;...&quot; /&gt; lines. To pin another version, set the kit's version property instead (for example &lt;MSKit_PackageVersion_XunitV3&gt;), or turn the kit's versions off with &lt;MSKit_ImplicitPackageVersions&gt;False&lt;/MSKit_ImplicitPackageVersions&gt;.%0ATo bypass this check: &lt;MSKit_SkipAudit_ImplicitPackageDuplicates&gt;True&lt;/MSKit_SkipAudit_ImplicitPackageDuplicates&gt;"
            File="$(MSBuildProjectFullPath)" />
diff --git a/kit/.toolkit/msbuild/DragoAnt.MSBuildKit/audit/audit.prerelease.packages.targets b/kit/.toolkit/msbuild/DragoAnt.MSBuildKit/audit/audit.prerelease.packages.targets
index 534e94f..e84b7bf 100644
--- a/kit/.toolkit/msbuild/DragoAnt.MSBuildKit/audit/audit.prerelease.packages.targets
+++ b/kit/.toolkit/msbuild/DragoAnt.MSBuildKit/audit/audit.prerelease.packages.targets
@@ -1,6 +1,6 @@
 <Project>
 
-  <!-- MSKIT_PRE001: a stable-branch build references a prerelease version of one of your own
+  <!-- MSKITPRE001: a stable-branch build references a prerelease version of one of your own
        packages (ids starting with MSKit_PrereleasePackagePrefix). Warning by default;
        MSKit_PrereleasePackageCheckAsWarning=false makes it an error. -->
 
@@ -18,10 +18,10 @@
     <PropertyGroup>
       <_MSKit_PrereleaseText>Prerelease $(MSKit_PrereleasePackagePrefix)* packages referenced on stable branch '$(MSKit_Branch)':%0A@(_MSKit_PrereleaseReferences->'  %(Identity) %(Version)', '%0A')%0AFix: replace them with stable versions in Directory.Packages.props or the csproj.</_MSKit_PrereleaseText>
     </PropertyGroup>
-    <Warning Code="MSKIT_PRE001"
+    <Warning Code="MSKITPRE001" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskitpre001"
              Condition="'@(_MSKit_PrereleaseReferences)'!='' AND '$(MSKit_PrereleasePackageCheckAsWarning)'=='true'"
              Text="$(_MSKit_PrereleaseText)" />
-    <Error Code="MSKIT_PRE001"
+    <Error Code="MSKITPRE001" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskitpre001"
            Condition="'@(_MSKit_PrereleaseReferences)'!='' AND '$(MSKit_PrereleasePackageCheckAsWarning)'!='true'"
            Text="$(_MSKit_PrereleaseText)" />
   </Target>
diff --git a/kit/.toolkit/msbuild/DragoAnt.MSBuildKit/audit/audit.restrict.packages.targets b/kit/.toolkit/msbuild/DragoAnt.MSBuildKit/audit/audit.restrict.packages.targets
index 4fba85c..f1ad97e 100644
--- a/kit/.toolkit/msbuild/DragoAnt.MSBuildKit/audit/audit.restrict.packages.targets
+++ b/kit/.toolkit/msbuild/DragoAnt.MSBuildKit/audit/audit.restrict.packages.targets
@@ -1,6 +1,6 @@
 <Project InitialTargets="RestrictPackageReferenceAudit">
 
-  <!-- MSKIT_RES001 / MSKIT_RES002: a referenced package is banned (Type="Error") or discouraged
+  <!-- MSKITRES001 / MSKITRES002: a referenced package is banned (Type="Error") or discouraged
        (Type="Warning") by an MSKit_RestrictPackageReference item:
          <MSKit_RestrictPackageReference Include="Moq" Type="Error" Message="Use NSubstitute." />
        SkipGlobalRestriction="True" on one PackageReference downgrades it to a warning. -->
@@ -13,17 +13,17 @@
                                         SkipGlobalRestriction="True" />
     </ItemGroup>
 
-    <Error Code="MSKIT_RES001"
+    <Error Code="MSKITRES001" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskitres001"
       Condition="'%(MSKit_PackageReferenceNotAllowed.Identity)'!='' And '%(MSKit_PackageReferenceNotAllowed.Type)'=='Error' And '%(MSKit_PackageReferenceNotAllowed.SkipGlobalRestriction)'!='True'"
       Text="Package '%(MSKit_PackageReferenceNotAllowed.Identity)' is prohibited. %(MSKit_PackageReferenceNotAllowed.Message)%0AFix: remove the PackageReference or use the suggested alternative. To allow this one reference, add SkipGlobalRestriction=&quot;True&quot; to it."
       File="$(MSBuildProjectFullPath)" />
 
-    <Warning Code="MSKIT_RES001"
+    <Warning Code="MSKITRES001" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskitres001"
       Condition="'%(MSKit_PackageReferenceNotAllowed.Identity)'!='' And '%(MSKit_PackageReferenceNotAllowed.Type)'=='Error' And '%(MSKit_PackageReferenceNotAllowed.SkipGlobalRestriction)'=='True'"
       Text="Package '%(MSKit_PackageReferenceNotAllowed.Identity)' is prohibited (allowed here by SkipGlobalRestriction). %(MSKit_PackageReferenceNotAllowed.Message)"
       File="$(MSBuildProjectFullPath)" />
 
-    <Warning Code="MSKIT_RES002"
+    <Warning Code="MSKITRES002" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskitres002"
       Condition="'%(MSKit_PackageReferenceNotAllowed.Identity)'!='' And '%(MSKit_PackageReferenceNotAllowed.Type)'=='Warning' And '%(MSKit_PackageReferenceNotAllowed.SkipGlobalRestriction)'!='True'"
       Text="Package '%(MSKit_PackageReferenceNotAllowed.Identity)' is discouraged. %(MSKit_PackageReferenceNotAllowed.Message)%0ATo silence this for one reference, add SkipGlobalRestriction=&quot;True&quot; to it."
       File="$(MSBuildProjectFullPath)" />
diff --git a/kit/.toolkit/msbuild/DragoAnt.MSBuildKit/audit/audit.restrict.reference.targets b/kit/.toolkit/msbuild/DragoAnt.MSBuildKit/audit/audit.restrict.reference.targets
index 6e84fa3..462ab83 100644
--- a/kit/.toolkit/msbuild/DragoAnt.MSBuildKit/audit/audit.restrict.reference.targets
+++ b/kit/.toolkit/msbuild/DragoAnt.MSBuildKit/audit/audit.restrict.reference.targets
@@ -1,6 +1,6 @@
 <Project InitialTargets="RestrictProjectReferenceAudit;RestrictAllowedPackageReferenceAudit">
 
-  <!-- MSKIT_RES003 / MSKIT_RES004: allow-list mode. With MSKit_RestrictProjectReferences=True
+  <!-- MSKITRES003 / MSKITRES004: allow-list mode. With MSKit_RestrictProjectReferences=True
        (or MSKit_RestrictPackageReferences=True, or MSKit_RestrictReferences=True for both), every
        reference must carry Allowed="True". -->
 
@@ -15,7 +15,7 @@
       <MSKit_ProjectReferenceNotAllowed Include="@(ProjectReference)"
                                         Condition=" '%(ProjectReference.Allowed)'!='True' AND '@(ProjectReference)'!='' AND '%(Identity)'!=''" />
     </ItemGroup>
-    <Error Code="MSKIT_RES003"
+    <Error Code="MSKITRES003" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskitres003"
            Condition="'%(MSKit_ProjectReferenceNotAllowed.Identity)'!=''"
            Text="ProjectReference '%(MSKit_ProjectReferenceNotAllowed.Identity)' is not allowed in this project.%0AFix: remove it, or mark it allowed: &lt;ProjectReference Include=&quot;%(MSKit_ProjectReferenceNotAllowed.Identity)&quot; Allowed=&quot;True&quot; /&gt;"
            File="$(MSBuildProjectFullPath)" />
@@ -26,7 +26,7 @@
       <_MSKit_PackageReferenceNotAllowListed Include="@(PackageReference)"
                                              Condition=" '%(PackageReference.Allowed)'!='True' AND '@(PackageReference)'!='' AND '%(Identity)'!=''" />
     </ItemGroup>
-    <Error Code="MSKIT_RES004"
+    <Error Code="MSKITRES004" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskitres004"
            Condition="'%(_MSKit_PackageReferenceNotAllowListed.Identity)'!=''"
            Text="PackageReference '%(_MSKit_PackageReferenceNotAllowListed.Identity)' is not allowed in this project.%0AFix: remove it, or mark it allowed: &lt;PackageReference Include=&quot;%(_MSKit_PackageReferenceNotAllowListed.Identity)&quot; Allowed=&quot;True&quot; /&gt;"
            File="$(MSBuildProjectFullPath)" />
diff --git a/kit/.toolkit/msbuild/DragoAnt.MSBuildKit/audit/audit.shared.properties.targets b/kit/.toolkit/msbuild/DragoAnt.MSBuildKit/audit/audit.shared.properties.targets
index eeda662..d86f043 100644
--- a/kit/.toolkit/msbuild/DragoAnt.MSBuildKit/audit/audit.shared.properties.targets
+++ b/kit/.toolkit/msbuild/DragoAnt.MSBuildKit/audit/audit.shared.properties.targets
@@ -30,29 +30,29 @@
       <_MSKit_TFs_ProjNodeCount>@(_MSKit_TFs_NodeCheckXmlResult-&gt;Count())</_MSKit_TFs_ProjNodeCount>
     </PropertyGroup>
 
-    <!-- MSKIT_SHARED006: csproj <TargetFramework> declares the SAME value as the shared config.
+    <!-- MSKITSHARED006: csproj <TargetFramework> declares the SAME value as the shared config.
          Pure literal duplicate; not bypassable. Reads MSKit_TargetFramework_Proj (set by Core
          tfm.routine.props at props phase). -->
-    <Error Code="MSKIT_SHARED006"
+    <Error Code="MSKITSHARED006" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskitshared006"
            Condition="'$(MSKit_TargetFramework_Proj)'!=''
                       AND '$(MSKit_TargetFramework_Shared)'!=''
                       AND '$(MSKit_TargetFramework_Proj)'=='$(MSKit_TargetFramework_Shared)'"
            File="$(MSBuildProjectFullPath)"
            Text="csproj '$(MSBuildProjectName)' declares &lt;TargetFramework&gt;$(MSKit_TargetFramework_Proj)&lt;/TargetFramework&gt; which equals Directory.Build.props's &lt;TargetFramework&gt;$(MSKit_TargetFramework_Shared)&lt;/TargetFramework&gt; - the csproj declaration is redundant.%0AFix: remove this from the csproj &lt;PropertyGroup&gt;:%0A  &lt;TargetFramework&gt;$(MSKit_TargetFramework_Proj)&lt;/TargetFramework&gt;%0ADirectory.Build.props is the single source of truth.%0AThis check is not bypassable; pure literal duplication is always a code smell." />
 
-    <!-- MSKIT_SHARED007: csproj <TargetFrameworks> declares the SAME value as the shared config.
+    <!-- MSKITSHARED007: csproj <TargetFrameworks> declares the SAME value as the shared config.
          Pure literal duplicate; not bypassable. -->
-    <Error Code="MSKIT_SHARED007"
+    <Error Code="MSKITSHARED007" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskitshared007"
            Condition="'$(MSKit_TargetFrameworks_Proj)'!=''
                       AND '$(MSKit_TargetFrameworks_Shared)'!=''
                       AND '$(MSKit_TargetFrameworks_Proj)'=='$(MSKit_TargetFrameworks_Shared)'"
            File="$(MSBuildProjectFullPath)"
            Text="csproj '$(MSBuildProjectName)' declares &lt;TargetFrameworks&gt;$(MSKit_TargetFrameworks_Proj)&lt;/TargetFrameworks&gt; which equals Directory.Build.props's &lt;TargetFrameworks&gt;$(MSKit_TargetFrameworks_Shared)&lt;/TargetFrameworks&gt; - the csproj declaration is redundant.%0AFix: remove this from the csproj &lt;PropertyGroup&gt;:%0A  &lt;TargetFrameworks&gt;$(MSKit_TargetFrameworks_Proj)&lt;/TargetFrameworks&gt;%0ADirectory.Build.props is the single source of truth.%0AThis check is not bypassable; pure literal duplication is always a code smell." />
 
-    <!-- MSKIT_SHARED008: csproj <TargetFramework> overrides DBP's <TargetFramework> with a different value.
+    <!-- MSKITSHARED008: csproj <TargetFramework> overrides DBP's <TargetFramework> with a different value.
          Warning by default; bypass with MSKit_SkipAudit_TargetFrameworkOverride=True.
          Does not fire when the csproj switches shape. -->
-    <Warning Code="MSKIT_SHARED008"
+    <Warning Code="MSKITSHARED008" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskitshared008"
              Condition="'$(MSKit_SkipAudit_TargetFrameworkOverride)'!='True'
                         AND '$(MSKit_TargetFramework_Proj)'!=''
                         AND '$(MSKit_TargetFramework_Shared)'!=''
@@ -61,10 +61,10 @@
              File="$(MSBuildProjectFullPath)"
              Text="csproj '$(MSBuildProjectName)' declares &lt;TargetFramework&gt;$(MSKit_TargetFramework_Proj)&lt;/TargetFramework&gt; but Directory.Build.props centralizes &lt;TargetFramework&gt;$(MSKit_TargetFramework_Shared)&lt;/TargetFramework&gt; as the default.%0ARecommended: remove the csproj-level &lt;TargetFramework&gt; declaration (DBP is the single source of truth).%0ATo override intentionally, add to the csproj &lt;PropertyGroup&gt;:%0A  &lt;MSKit_SkipAudit_TargetFrameworkOverride&gt;True&lt;/MSKit_SkipAudit_TargetFrameworkOverride&gt;" />
 
-    <!-- MSKIT_SHARED009: csproj <TargetFrameworks> overrides DBP's <TargetFrameworks> with a different value.
+    <!-- MSKITSHARED009: csproj <TargetFrameworks> overrides DBP's <TargetFrameworks> with a different value.
          Warning by default; bypass with MSKit_SkipAudit_TargetFrameworkOverride=True.
          Does not fire when the csproj switches shape. -->
-    <Warning Code="MSKIT_SHARED009"
+    <Warning Code="MSKITSHARED009" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskitshared009"
              Condition="'$(MSKit_SkipAudit_TargetFrameworkOverride)'!='True'
                         AND '$(MSKit_TargetFrameworks_Proj)'!=''
                         AND '$(MSKit_TargetFrameworks_Shared)'!=''
@@ -73,12 +73,12 @@
              File="$(MSBuildProjectFullPath)"
              Text="csproj '$(MSBuildProjectName)' declares &lt;TargetFrameworks&gt;$(MSKit_TargetFrameworks_Proj)&lt;/TargetFrameworks&gt; but Directory.Build.props centralizes &lt;TargetFrameworks&gt;$(MSKit_TargetFrameworks_Shared)&lt;/TargetFrameworks&gt; as the default.%0ARecommended: remove the csproj-level &lt;TargetFrameworks&gt; declaration (DBP is the single source of truth).%0ATo override intentionally, add to the csproj &lt;PropertyGroup&gt;:%0A  &lt;MSKit_SkipAudit_TargetFrameworkOverride&gt;True&lt;/MSKit_SkipAudit_TargetFrameworkOverride&gt;" />
 
-    <!-- MSKIT_SHARED010: csproj declares BOTH <TargetFramework> AND <TargetFrameworks>.
+    <!-- MSKITSHARED010: csproj declares BOTH <TargetFramework> AND <TargetFrameworks>.
          Error, non-bypassable. SDK silently ignores <TargetFramework>
          when <TargetFrameworks> is non-empty (cross-targeting wins); the redundant declaration
          is a code smell that should be fixed at source. Uses NODE-presence count (not value)
          so even the legacy <TargetFramework></TargetFramework> "clear" trick fires the audit. -->
-    <Error Code="MSKIT_SHARED010"
+    <Error Code="MSKITSHARED010" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskitshared010"
            Condition="$(_MSKit_TF_ProjNodeCount) &gt; 0 AND $(_MSKit_TFs_ProjNodeCount) &gt; 0"
            File="$(MSBuildProjectFullPath)"
            Text="csproj '$(MSBuildProjectName)' declares BOTH &lt;TargetFramework&gt; AND &lt;TargetFrameworks&gt; in the same project. SDK silently ignores &lt;TargetFramework&gt; when &lt;TargetFrameworks&gt; is non-empty.%0AFix: remove one of these from the csproj &lt;PropertyGroup&gt; - pick the shape you actually want:%0A  &lt;TargetFramework&gt;$(MSKit_TargetFramework_Proj)&lt;/TargetFramework&gt;%0A    -- OR --%0A  &lt;TargetFrameworks&gt;$(MSKit_TargetFrameworks_Proj)&lt;/TargetFrameworks&gt;%0AThis check is not bypassable; declaring both is always wrong." />
@@ -87,7 +87,7 @@
     <PropertyGroup>
       <MSKit_SkipAudit_TreatWarningsAsErrors Condition="'$(MSKit_IsDevEnv)'!='True'">True</MSKit_SkipAudit_TreatWarningsAsErrors>
     </PropertyGroup>
-    <Error Code="MSKIT_SHARED020"
+    <Error Code="MSKITSHARED020" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskitshared020"
            Condition="'$(MSKit_SkipAudit_TreatWarningsAsErrors)'!='True'
                       AND '$(MSKit_TreatWarningsAsErrors_Shared)'!=''
                       AND '$(TreatWarningsAsErrors)'!='$(MSKit_TreatWarningsAsErrors_Shared)'"
diff --git a/kit/.toolkit/msbuild/DragoAnt.MSBuildKit/audit/audit.version.targets b/kit/.toolkit/msbuild/DragoAnt.MSBuildKit/audit/audit.version.targets
index aaea8ee..125aea7 100644
--- a/kit/.toolkit/msbuild/DragoAnt.MSBuildKit/audit/audit.version.targets
+++ b/kit/.toolkit/msbuild/DragoAnt.MSBuildKit/audit/audit.version.targets
@@ -1,8 +1,8 @@
 <Project InitialTargets="RestrictManualVersion;ValidateVersionTemplate;ValidateReleaseTag">
 
-  <!-- Checks for the version engine (version.props / version.targets). Codes MSKIT_VER001..007. -->
+  <!-- Checks for the version engine (version.props / version.targets). Codes MSKITVER001..007. -->
 
-  <!-- MSKIT_VER001: <Version> declared in the csproj while a template strategy is active. -->
+  <!-- MSKITVER001: <Version> declared in the csproj while a template strategy is active. -->
   <Target Name="RestrictManualVersion"
           Condition="'$(MSKit_VersionStrategy)'!='Manual'"
           BeforeTargets="Restore;Build;CoreCompile">
@@ -17,13 +17,13 @@
       <Output TaskParameter="Result" ItemName="_MSKit_VersionCheckNode" />
     </XmlPeek>
 
-    <Error Code="MSKIT_VER001"
+    <Error Code="MSKITVER001" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskitver001"
            Condition="@(_MSKit_VersionCheckNode->Count()) &gt; 0"
            Text="&lt;Version&gt; is declared in the project but MSKit_VersionStrategy='$(MSKit_VersionStrategy)' renders the version from a template, so the declared value is ignored.%0AFix: remove &lt;Version&gt; from the csproj (declare the next version as &lt;VersionPrefix&gt; in Directory.Version.props), or switch to manual versioning in Directory.Build.props:%0A  &lt;MSKit_VersionStrategy&gt;Manual&lt;/MSKit_VersionStrategy&gt;"
            File="$(MSBuildProjectFullPath)" />
   </Target>
 
-  <!-- MSKIT_VER002 / MSKIT_VER003: a template uses a placeholder the engine does not know. -->
+  <!-- MSKITVER002: a template uses a placeholder the engine does not know (MSKITVER003 is reserved, never reported). -->
   <Target Name="ValidateVersionTemplate"
           Condition="'$(MSKit_VersionStrategy)'!='Manual'">
 
@@ -56,35 +56,35 @@ Valid placeholders:
       <_MSKit_UnknownPlaceholder Include="@(_MSKit_TplNameItem)" Exclude="@(_MSKit_ValidPlaceholder)" />
     </ItemGroup>
 
-    <Error Code="MSKIT_VER002"
+    <Error Code="MSKITVER002" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskitver002"
            Condition="@(_MSKit_UnknownPlaceholder->Count()) &gt; 0"
            Text="A version template contains unknown placeholder(s): @(_MSKit_UnknownPlaceholder -> '{%(Identity)}', ', ').%0ATemplates: MSKit_VersionTemplate='$(MSKit_VersionTemplate)', MSKit_StableVersionTemplate='$(MSKit_StableVersionTemplate)', MSKit_ReleaseVersionTemplate='$(MSKit_ReleaseVersionTemplate)', MSKit_PullRequestVersionTemplate='$(MSKit_PullRequestVersionTemplate)'.%0A$(_MSKit_PlaceholderHelp)"
            File="$(MSBuildProjectFullPath)" />
   </Target>
 
-  <!-- MSKIT_VER004: the VersionTag strategy rendered an empty version. -->
+  <!-- MSKITVER004: the VersionTag strategy rendered an empty version. -->
   <Target Name="ValidateRenderedVersionForVersionTag"
           AfterTargets="RenderVersionFromTemplate"
           Condition="'$(MSKit_VersionStrategy)'=='VersionTag'">
-    <Error Code="MSKIT_VER004"
+    <Error Code="MSKITVER004" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskitver004"
            Condition="'$(Version)'==''"
            Text="MSKit_VersionStrategy='VersionTag' but VersionTag is empty.%0AFix: pass it on the command line (-p:VersionTag=1.2.3) or use MSKit_VersionStrategy=ReleaseTag, which reads the version from the release tag."
            File="$(MSBuildProjectFullPath)" />
   </Target>
 
-  <!-- MSKIT_VER006: a release tag that is not SemVer 2.0. MSKIT_VER007: its version core differs
+  <!-- MSKITVER006: a release tag that is not SemVer 2.0. MSKITVER007: its version core differs
        from the VersionPrefix the repository declares. -->
   <Target Name="ValidateReleaseTag"
           Condition="'$(MSKit_IsReleaseTag)'=='True' AND '$(MSKit_ExplicitVersion)'=='' AND '$(MSKit_VersionStrategy)'!='Manual' AND '$(MSKit_VersionStrategy)'!='DevEnv'"
           BeforeTargets="Restore;Build">
-    <Error Code="MSKIT_VER006"
+    <Error Code="MSKITVER006" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskitver006"
            Condition="'$(MSKit_IsReleaseTagValid)'!='true'"
            Text="Release tag '$(MSKit_ReleaseTagRaw)' is not a valid version. After removing a leading 'v' it must be SemVer 2.0: MAJOR.MINOR.PATCH with an optional -prerelease and +metadata (for example v2.1.0 or 2.1.0-beta.1).%0AFix: delete the tag and the GitHub release, then create a release whose tag is a version."
            File="$(MSBuildProjectFullPath)" />
     <PropertyGroup Condition="'$(MSKit_IsReleaseTagValid)'=='true'">
       <_MSKit_ReleaseTagCore>$([System.Text.RegularExpressions.Regex]::Match('$(MSKit_ReleaseTag)', '^\d+\.\d+\.\d+').Value)</_MSKit_ReleaseTagCore>
     </PropertyGroup>
-    <Warning Code="MSKIT_VER007"
+    <Warning Code="MSKITVER007" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskitver007"
              Condition="'$(MSKit_SkipAudit_ReleaseTagPrefix)'!='True' AND '$(_MSKit_ReleaseTagCore)'!='' AND '$(MSKit_DeclaredVersionPrefix)'!='' AND '$(MSKit_DeclaredVersionPrefix)'!='$(_MSKit_ReleaseTagCore)'"
              Text="Release tag '$(MSKit_ReleaseTagRaw)' has version core $(_MSKit_ReleaseTagCore), but the repository declares VersionPrefix $(MSKit_DeclaredVersionPrefix).%0AFix: bump &lt;VersionPrefix&gt; in Directory.Version.props after the release so branch and pull-request builds sort above it. Set MSKit_SkipAudit_ReleaseTagPrefix=True to silence this."
              File="$(MSBuildProjectFullPath)" />
diff --git a/kit/.toolkit/msbuild/DragoAnt.MSBuildKit/twae.shared.init.props b/kit/.toolkit/msbuild/DragoAnt.MSBuildKit/twae.shared.init.props
index ffddb18..072f863 100644
--- a/kit/.toolkit/msbuild/DragoAnt.MSBuildKit/twae.shared.init.props
+++ b/kit/.toolkit/msbuild/DragoAnt.MSBuildKit/twae.shared.init.props
@@ -1,6 +1,6 @@
 <Project>
 
-  <!-- Captured before the csproj body so MSKIT_SHARED020 can compare against the shared value. -->
+  <!-- Captured before the csproj body so MSKITSHARED020 can compare against the shared value. -->
   <PropertyGroup>
     <MSKit_TreatWarningsAsErrors_Shared>$(TreatWarningsAsErrors)</MSKit_TreatWarningsAsErrors_Shared>
   </PropertyGroup>
diff --git a/kit/.toolkit/msbuild/DragoAnt.MSBuildKit/version.props b/kit/.toolkit/msbuild/DragoAnt.MSBuildKit/version.props
index 6e356cf..83c5779 100644
--- a/kit/.toolkit/msbuild/DragoAnt.MSBuildKit/version.props
+++ b/kit/.toolkit/msbuild/DragoAnt.MSBuildKit/version.props
@@ -97,7 +97,7 @@
     <_MSKit_Ph_versionTag>$(VersionTag)</_MSKit_Ph_versionTag>
     <_MSKit_Ph_releaseTag Condition="'$(MSKit_IsReleaseTagValid)'=='true'">$(MSKit_ReleaseTag)</_MSKit_Ph_releaseTag>
     <!-- An invalid tag renders a valid placeholder so restore does not fail first with an opaque
-         error; ValidateReleaseTag then stops the build with MSKIT_VER006. -->
+         error; ValidateReleaseTag then stops the build with MSKITVER006. -->
     <_MSKit_Ph_releaseTag Condition="'$(MSKit_IsReleaseTagValid)'!='true'">0.0.0-invalid-release-tag</_MSKit_Ph_releaseTag>
     <_MSKit_Ph_prNumber>$(MSKit_PullRequestNumber)</_MSKit_Ph_prNumber>
     <_MSKit_Ph_buildNumber>$(MSKit_BuildNumber)</_MSKit_Ph_buildNumber>
diff --git a/manager/.toolkit/msbuild/DragoAnt.MSBuildKit.Core/audit/audit.autodetect-mutex.targets b/manager/.toolkit/msbuild/DragoAnt.MSBuildKit.Core/audit/audit.autodetect-mutex.targets
index 74fc36e..d0ef456 100644
--- a/manager/.toolkit/msbuild/DragoAnt.MSBuildKit.Core/audit/audit.autodetect-mutex.targets
+++ b/manager/.toolkit/msbuild/DragoAnt.MSBuildKit.Core/audit/audit.autodetect-mutex.targets
@@ -1,13 +1,13 @@
 <Project>
 
-  <!-- MSKIT_CORE001: the project name matched more than one auto-detect regex. -->
+  <!-- MSKITCORE001: the project name matched more than one auto-detect regex. -->
   <Target Name="ValidateAutoDetectedProjectTypeMutex"
           BeforeTargets="CoreCompile;Build"
           Condition="@(MSKit_AutoDetectedProjectType-&gt;Count()) &gt; 1">
     <PropertyGroup>
       <_MSKit_AutoDetectedTypes>@(MSKit_AutoDetectedProjectType, ', ')</_MSKit_AutoDetectedTypes>
     </PropertyGroup>
-    <Error Code="MSKIT_CORE001"
+    <Error Code="MSKITCORE001" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskitcore001"
            File="$(MSBuildProjectFullPath)"
            Text="Project '$(MSBuildProjectName)' auto-detected as MULTIPLE project types: $(_MSKit_AutoDetectedTypes).%0AA project can be exactly ONE type.%0AFix ONE of:%0A  1. Rename the project so its name matches only ONE auto-detect regex%0A  2. Override the conflicting MSKit_*ProjectNameRegex in Directory.Build.props to exclude this project name%0A  3. Set the corresponding MSKit_Disable*AutoDetect=true in the csproj and import the explicit endpoint instead (e.g. MSKit_DisableCodeAnalyzerAutoDetect=true + Import &quot;$(CodeAnalyzerCommonPropsPath)&quot;)" />
   </Target>
diff --git a/manager/.toolkit/msbuild/DragoAnt.MSBuildKit.Core/audit/audit.roslyn-satellites.targets b/manager/.toolkit/msbuild/DragoAnt.MSBuildKit.Core/audit/audit.roslyn-satellites.targets
index d5b0b61..dd97fe2 100644
--- a/manager/.toolkit/msbuild/DragoAnt.MSBuildKit.Core/audit/audit.roslyn-satellites.targets
+++ b/manager/.toolkit/msbuild/DragoAnt.MSBuildKit.Core/audit/audit.roslyn-satellites.targets
@@ -1,13 +1,13 @@
 <Project>
 
-  <!-- MSKIT_ROSLYN001..003: a project name matched a Roslyn auto-detect regex, but the kit part
+  <!-- MSKITROSLYN001..003: a project name matched a Roslyn auto-detect regex, but the kit part
        that wires that project type is not installed. -->
 
   <Target Name="ValidateCodeAnalyzerSatelliteAttached"
           BeforeTargets="CoreCompile;Build"
           Condition="'$(MSKit_IsCodeAnalyzerAutoDetected)'=='True'
                       AND '$(MSKit_CodeAnalyzerSatelliteAttached)'!='true'">
-    <Error Code="MSKIT_ROSLYN001"
+    <Error Code="MSKITROSLYN001" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskitroslyn001"
            File="$(MSBuildProjectFullPath)"
            Text="Project '$(MSBuildProjectName)' name matches the CodeAnalyzer auto-detect regex '$(_MSKit_CodeAnalyzerProjectNameRegex_Shared)' but the kit part 'DragoAnt.MSBuildKit.Project.CodeAnalyzer' is not installed.%0AFix: pwsh .toolkit/update.ps1 -Add Project.CodeAnalyzer   (or: sh .toolkit/update.sh --add Project.CodeAnalyzer)%0AOr, if this project is not a Roslyn analyzer, rename it or set MSKit_DisableCodeAnalyzerAutoDetect=true in the csproj." />
   </Target>
@@ -16,7 +16,7 @@
           BeforeTargets="CoreCompile;Build"
           Condition="'$(MSKit_IsCodeFixerAutoDetected)'=='True'
                       AND '$(MSKit_CodeFixerSatelliteAttached)'!='true'">
-    <Error Code="MSKIT_ROSLYN002"
+    <Error Code="MSKITROSLYN002" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskitroslyn002"
            File="$(MSBuildProjectFullPath)"
            Text="Project '$(MSBuildProjectName)' name matches the CodeFixer auto-detect regex '$(_MSKit_CodeFixerProjectNameRegex_Shared)' but the kit part 'DragoAnt.MSBuildKit.Project.CodeFixer' is not installed.%0AFix: pwsh .toolkit/update.ps1 -Add Project.CodeFixer   (or: sh .toolkit/update.sh --add Project.CodeFixer)%0AOr, if this project is not a Roslyn code-fix provider, rename it or set MSKit_DisableCodeFixerAutoDetect=true in the csproj." />
   </Target>
@@ -25,7 +25,7 @@
           BeforeTargets="CoreCompile;Build"
           Condition="'$(MSKit_IsSourceGeneratorAutoDetected)'=='True'
                       AND '$(MSKit_SourceGeneratorSatelliteAttached)'!='true'">
-    <Error Code="MSKIT_ROSLYN003"
+    <Error Code="MSKITROSLYN003" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskitroslyn003"
            File="$(MSBuildProjectFullPath)"
            Text="Project '$(MSBuildProjectName)' name matches the SourceGenerator auto-detect regex '$(_MSKit_SourceGeneratorProjectNameRegex_Shared)' but the kit part 'DragoAnt.MSBuildKit.Project.SourceGenerator' is not installed.%0AFix: pwsh .toolkit/update.ps1 -Add Project.SourceGenerator   (or: sh .toolkit/update.sh --add Project.SourceGenerator)%0AOr, if this project is not a Roslyn source generator, rename it or set MSKit_DisableSourceGeneratorAutoDetect=true in the csproj." />
   </Target>
diff --git a/manager/.toolkit/msbuild/DragoAnt.MSBuildKit.Core/core.common.props b/manager/.toolkit/msbuild/DragoAnt.MSBuildKit.Core/core.common.props
index cac50d6..f114686 100644
--- a/manager/.toolkit/msbuild/DragoAnt.MSBuildKit.Core/core.common.props
+++ b/manager/.toolkit/msbuild/DragoAnt.MSBuildKit.Core/core.common.props
@@ -2,6 +2,7 @@
 
   <PropertyGroup>
     <MSKit_Diagnostic Condition="'$(MSKit_Diagnostic)'==''">false</MSKit_Diagnostic>
+    <MSKit_CodesHelpBaseUrl Condition="'$(MSKit_CodesHelpBaseUrl)'==''">https://github.com/DragoAnt/MSBuildKit/blob/main/docs/reference/codes.md</MSKit_CodesHelpBaseUrl>
     <!-- True on a developer machine; the Vcs.GitHub part flips it to False on GitHub Actions. -->
     <MSKit_IsDevEnv Condition="'$(MSKit_IsDevEnv)'==''">True</MSKit_IsDevEnv>
 
diff --git a/manager/.toolkit/msbuild/DragoAnt.MSBuildKit.Packaging/audit/audit.package.targets b/manager/.toolkit/msbuild/DragoAnt.MSBuildKit.Packaging/audit/audit.package.targets
index 563bc1e..bf15e43 100644
--- a/manager/.toolkit/msbuild/DragoAnt.MSBuildKit.Packaging/audit/audit.package.targets
+++ b/manager/.toolkit/msbuild/DragoAnt.MSBuildKit.Packaging/audit/audit.package.targets
@@ -1,8 +1,8 @@
 <Project>
 
-  <!-- nuget.org package checks, MSKIT_PKG001..019, run by `dotnet pack`. They are warnings on a
+  <!-- nuget.org package checks, MSKITPKG001..019, run by `dotnet pack`. They are warnings on a
        developer machine and errors on CI (MSKit_PackageChecksAsErrors). Turn single checks off with
-       MSKit_SkipPackageChecks=MSKIT_PKG004;MSKIT_PKG016 (or by listing the code in NoWarn), or all
+       MSKit_SkipPackageChecks=MSKITPKG004;MSKITPKG016 (or by listing the code in NoWarn), or all
        of them with MSKit_SkipPackageChecks=All. -->
 
   <PropertyGroup>
@@ -29,7 +29,7 @@
       <Output TaskParameter="HtmlTags" PropertyName="_MSKit_HtmlTags" />
       <Output TaskParameter="Alerts" PropertyName="_MSKit_Alerts" />
       <Output TaskParameter="HasMermaid" PropertyName="_MSKit_HasMermaid" />
-      <Output TaskParameter="IconIsPng" PropertyName="_MSKit_IconIsPng" />
+      <Output TaskParameter="IconFormat" PropertyName="_MSKit_IconFormat" />
       <Output TaskParameter="IconWidth" PropertyName="_MSKit_IconWidth" />
       <Output TaskParameter="IconHeight" PropertyName="_MSKit_IconHeight" />
     </MSKit_PackageAssets>
@@ -47,61 +47,61 @@
     </PropertyGroup>
 
     <ItemGroup>
-      <_MSKit_PkgFinding Include="MSKIT_PKG001" Condition="'$(_MSKit_DescriptionIsPlaceholder)'=='True'"
+      <_MSKit_PkgFinding Include="MSKITPKG001" Condition="'$(_MSKit_DescriptionIsPlaceholder)'=='True'"
                          Text="Package '$(PackageId)' has no real Description ('$(_MSKit_Description)'). nuget.org search shows it first: say what the package does and what sets it apart, in one or two sentences."
                          Rule="$(_MSKit_PkgRules)#description" />
-      <_MSKit_PkgFinding Include="MSKIT_PKG002" Condition="'$(_MSKit_DescriptionIsPlaceholder)'!='True' AND $(_MSKit_Description.Length) &lt; $(MSKit_PackageDescriptionMinLength)"
+      <_MSKit_PkgFinding Include="MSKITPKG002" Condition="'$(_MSKit_DescriptionIsPlaceholder)'!='True' AND $(_MSKit_Description.Length) &lt; $(MSKit_PackageDescriptionMinLength)"
                          Text="Package '$(PackageId)' Description is $(_MSKit_Description.Length) characters ('$(_MSKit_Description)'); write at least $(MSKit_PackageDescriptionMinLength): what it does and for whom (MSKit_PackageDescriptionMinLength sets the bar)."
                          Rule="$(_MSKit_PkgRules)#description" />
-      <_MSKit_PkgFinding Include="MSKIT_PKG003" Condition="'$(PackageReadmeFile)'==''"
+      <_MSKit_PkgFinding Include="MSKITPKG003" Condition="'$(PackageReadmeFile)'==''"
                          Text="Package '$(PackageId)' ships no README. Add package.readme.md next to the csproj: what it is, how to start, a short example, where to give feedback."
                          Rule="$(_MSKit_PkgRules)#readme" />
-      <_MSKit_PkgFinding Include="MSKIT_PKG004" Condition="'$(PackageTags)'==''"
+      <_MSKit_PkgFinding Include="MSKITPKG004" Condition="'$(PackageTags)'==''"
                          Text="Package '$(PackageId)' has no PackageTags. Add a few search terms that are not already in the package id."
                          Rule="$(_MSKit_PkgRules)#tags" />
-      <_MSKit_PkgFinding Include="MSKIT_PKG005" Condition="'$(PackageIcon)'==''"
-                         Text="Package '$(PackageId)' has no icon. Set PackageIconPath to a 128x128 PNG (the company layer of the kit sets one for every package)."
+      <_MSKit_PkgFinding Include="MSKITPKG005" Condition="'$(PackageIcon)'==''"
+                         Text="Package '$(PackageId)' has no icon. Set PackageIconPath to a 128x128 PNG or JPEG (the company layer of the kit sets one for every package)."
                          Rule="$(_MSKit_PkgRules)#icon" />
-      <_MSKit_PkgFinding Include="MSKIT_PKG006" Condition="'$(PackageLicenseExpression)'=='' AND '$(PackageLicenseFile)'==''"
+      <_MSKit_PkgFinding Include="MSKITPKG006" Condition="'$(PackageLicenseExpression)'=='' AND '$(PackageLicenseFile)'==''"
                          Text="Package '$(PackageId)' has no licence. Without one nobody may use it. Set PackageLicenseExpression to an SPDX id (for example MIT)."
                          Rule="$(_MSKit_PkgRules)#licensing" />
-      <_MSKit_PkgFinding Include="MSKIT_PKG007" Condition="'$(PackageLicenseUrl)'!=''"
+      <_MSKit_PkgFinding Include="MSKITPKG007" Condition="'$(PackageLicenseUrl)'!=''"
                          Text="Package '$(PackageId)' uses the deprecated PackageLicenseUrl. Replace it with PackageLicenseExpression (an SPDX id) or PackageLicenseFile."
                          Rule="$(_MSKit_PkgRules)#licensing" />
-      <_MSKit_PkgFinding Include="MSKIT_PKG008" Condition="'$(PackageIconUrl)'!=''"
+      <_MSKit_PkgFinding Include="MSKITPKG008" Condition="'$(PackageIconUrl)'!=''"
                          Text="Package '$(PackageId)' uses the deprecated PackageIconUrl. Pack the image and point PackageIcon (or the kit's PackageIconPath) at it."
                          Rule="$(_MSKit_PkgRules)#icon" />
-      <_MSKit_PkgFinding Include="MSKIT_PKG009" Condition="'$(_MSKit_RelativeImages)'!=''"
+      <_MSKit_PkgFinding Include="MSKITPKG009" Condition="'$(_MSKit_RelativeImages)'!=''"
                          Text="The package README of '$(PackageId)' has relative images, which nuget.org does not render: $(_MSKit_RelativeImages). Use absolute https URLs from an allowed host."
                          Rule="$(_MSKit_PkgReadmeRules)#allowed-domains-for-images-and-badges" />
-      <_MSKit_PkgFinding Include="MSKIT_PKG010" Condition="'$(_MSKit_HtmlTags)'!=''"
+      <_MSKit_PkgFinding Include="MSKITPKG010" Condition="'$(_MSKit_HtmlTags)'!=''"
                          Text="The package README of '$(PackageId)' contains HTML, which nuget.org does not render: $(_MSKit_HtmlTags). Use Markdown instead."
                          Rule="$(_MSKit_PkgReadmeRules)#supported-markdown-features" />
-      <_MSKit_PkgFinding Include="MSKIT_PKG011" Condition="'$(_MSKit_Alerts)'!=''"
+      <_MSKit_PkgFinding Include="MSKITPKG011" Condition="'$(_MSKit_Alerts)'!=''"
                          Text="The package README of '$(PackageId)' uses GitHub alert blocks, which nuget.org shows as plain quotes: $(_MSKit_Alerts). Use a bold lead-in such as **Note:** instead."
                          Rule="$(_MSKit_PkgReadmeRules)#supported-markdown-features" />
-      <_MSKit_PkgFinding Include="MSKIT_PKG012" Condition="'$(_MSKit_DisallowedImages)'!=''"
+      <_MSKit_PkgFinding Include="MSKITPKG012" Condition="'$(_MSKit_DisallowedImages)'!=''"
                          Text="The package README of '$(PackageId)' loads images from hosts nuget.org blocks: $(_MSKit_DisallowedImages). Host them on an allowed domain (img.shields.io, raw.githubusercontent.com, ...)."
                          Rule="$(_MSKit_PkgReadmeRules)#allowed-domains-for-images-and-badges" />
-      <_MSKit_PkgFinding Include="MSKIT_PKG013" Condition="'$(_MSKit_PkgVersion)'!='' AND !$([System.Text.RegularExpressions.Regex]::IsMatch('$(_MSKit_PkgVersion)', '$(MSKit_SemVerRegex)'))"
+      <_MSKit_PkgFinding Include="MSKITPKG013" Condition="'$(_MSKit_PkgVersion)'!='' AND !$([System.Text.RegularExpressions.Regex]::IsMatch('$(_MSKit_PkgVersion)', '$(MSKit_SemVerRegex)'))"
                          Text="Package '$(PackageId)' version '$(_MSKit_PkgVersion)' is not SemVer 2.0 (MAJOR.MINOR.PATCH[-prerelease][+metadata])."
                          Rule="$(_MSKit_PkgRules)#package-version" />
-      <_MSKit_PkgFinding Include="MSKIT_PKG014" Condition="'$(_MSKit_RepoUrlFinal)'=='' OR '$(PackageProjectUrl)'==''"
+      <_MSKit_PkgFinding Include="MSKITPKG014" Condition="'$(_MSKit_RepoUrlFinal)'=='' OR '$(PackageProjectUrl)'==''"
                          Text="Package '$(PackageId)' has no repository or project URL. Set RepositoryUrl, or build from a git clone whose origin remote Source Link can read."
                          Rule="$(_MSKit_PkgRules)#repository-type-and-url" />
-      <_MSKit_PkgFinding Include="MSKIT_PKG015" Condition="'$(MSKit_PackageIconSourcePath)'!='' AND Exists('$(MSKit_PackageIconSourcePath)') AND ('$(_MSKit_IconIsPng)'!='True' OR '$(_MSKit_IconWidth)'!='$(MSKit_PackageIconSize)' OR '$(_MSKit_IconHeight)'!='$(MSKit_PackageIconSize)')"
-                         Text="Package '$(PackageId)' icon is not a $(MSKit_PackageIconSize)x$(MSKit_PackageIconSize) PNG (PNG: $(_MSKit_IconIsPng), size: $(_MSKit_IconWidth)x$(_MSKit_IconHeight))."
+      <_MSKit_PkgFinding Include="MSKITPKG015" Condition="'$(MSKit_PackageIconSourcePath)'!='' AND Exists('$(MSKit_PackageIconSourcePath)') AND (('$(_MSKit_IconFormat)'!='PNG' AND '$(_MSKit_IconFormat)'!='JPEG') OR '$(_MSKit_IconWidth)'!='$(MSKit_PackageIconSize)' OR '$(_MSKit_IconHeight)'!='$(MSKit_PackageIconSize)')"
+                         Text="Package '$(PackageId)' icon is not a $(MSKit_PackageIconSize)x$(MSKit_PackageIconSize) PNG or JPEG (format: $(_MSKit_IconFormat), size: $(_MSKit_IconWidth)x$(_MSKit_IconHeight))."
                          Rule="$(_MSKit_PkgRules)#icon" />
-      <_MSKit_PkgFinding Include="MSKIT_PKG016" Condition="'$(PackageReleaseNotes)'==''"
+      <_MSKit_PkgFinding Include="MSKITPKG016" Condition="'$(PackageReleaseNotes)'==''"
                          Text="Package '$(PackageId)' has no PackageReleaseNotes. Set them, or a link to the changelog (the kit links the releases page by default on GitHub, and on any host the generated readme knows with MSKit_PackageReadmeFrom)."
                          Rule="$(_MSKit_PkgRules)#release-notes" />
-      <_MSKit_PkgFinding Include="MSKIT_PKG017" Condition="'$(_MSKit_RelativeLinks)'!=''"
+      <_MSKit_PkgFinding Include="MSKITPKG017" Condition="'$(_MSKit_RelativeLinks)'!=''"
                          Text="The package README of '$(PackageId)' has relative links, which break on nuget.org: $(_MSKit_RelativeLinks). Use absolute URLs."
                          Rule="$(_MSKit_PkgReadmeRules)" />
-      <_MSKit_PkgFinding Include="MSKIT_PKG018" Condition="'$(_MSKit_LicenseIsOpen)'=='True' AND $(Copyright.ToLowerInvariant().Contains('all rights reserved'))"
+      <_MSKit_PkgFinding Include="MSKITPKG018" Condition="'$(_MSKit_LicenseIsOpen)'=='True' AND $(Copyright.ToLowerInvariant().Contains('all rights reserved'))"
                          Text="Package '$(PackageId)' is licensed '$(PackageLicenseExpression)' but its Copyright says 'all rights reserved' ('$(Copyright)'). Use 'Copyright (c) YEAR OWNER'."
                          Rule="$(_MSKit_PkgRules)#copyright" />
-      <_MSKit_PkgFinding Include="MSKIT_PKG019" Condition="'$(_MSKit_HasMermaid)'=='True'"
+      <_MSKit_PkgFinding Include="MSKITPKG019" Condition="'$(_MSKit_HasMermaid)'=='True'"
                          Text="The package README of '$(PackageId)' contains a Mermaid diagram, which nuget.org shows as code. Link to the diagram on GitHub instead."
                          Rule="$(_MSKit_PkgReadmeRules)#supported-markdown-features" />
     </ItemGroup>
@@ -114,11 +114,13 @@
 
     <Warning Condition="'@(_MSKit_PkgFinding)'!='' AND '$(MSKit_PackageChecksAsErrors)'!='True'"
              Code="%(_MSKit_PkgFinding.Identity)"
+             HelpLink="$(MSKit_CodesHelpBaseUrl)#$([System.String]::Copy('%(_MSKit_PkgFinding.Identity)').ToLowerInvariant())"
              Text="%(_MSKit_PkgFinding.Text) Rule: %(_MSKit_PkgFinding.Rule) (to skip: MSKit_SkipPackageChecks=%(_MSKit_PkgFinding.Identity))"
              File="$(MSBuildProjectFullPath)" />
     <Error Condition="'@(_MSKit_PkgFinding)'!='' AND '$(MSKit_PackageChecksAsErrors)'=='True'"
            ContinueOnError="ErrorAndContinue"
            Code="%(_MSKit_PkgFinding.Identity)"
+           HelpLink="$(MSKit_CodesHelpBaseUrl)#$([System.String]::Copy('%(_MSKit_PkgFinding.Identity)').ToLowerInvariant())"
            Text="%(_MSKit_PkgFinding.Text) Rule: %(_MSKit_PkgFinding.Rule) (to skip: MSKit_SkipPackageChecks=%(_MSKit_PkgFinding.Identity))"
            File="$(MSBuildProjectFullPath)" />
   </Target>
diff --git a/manager/.toolkit/msbuild/DragoAnt.MSBuildKit.Packaging/package.inspect.targets b/manager/.toolkit/msbuild/DragoAnt.MSBuildKit.Packaging/package.inspect.targets
index bdb9dd4..061477d 100644
--- a/manager/.toolkit/msbuild/DragoAnt.MSBuildKit.Packaging/package.inspect.targets
+++ b/manager/.toolkit/msbuild/DragoAnt.MSBuildKit.Packaging/package.inspect.targets
@@ -1,6 +1,6 @@
 <Project>
 
-  <!-- Mode="Inspect" reads the package README and icon for the MSKIT_PKG checks; Mode="GenerateReadme"
+  <!-- Mode="Inspect" reads the package README and icon for the MSKITPKG checks; Mode="GenerateReadme"
        writes the readme generated from MSKit_PackageReadmeFrom. The code is in package.tasks.cs.txt. -->
   <UsingTask TaskName="MSKit_PackageAssets"
              TaskFactory="RoslynCodeTaskFactory"
diff --git a/manager/.toolkit/msbuild/DragoAnt.MSBuildKit.Packaging/package.readme.targets b/manager/.toolkit/msbuild/DragoAnt.MSBuildKit.Packaging/package.readme.targets
index 38995aa..228ffa6 100644
--- a/manager/.toolkit/msbuild/DragoAnt.MSBuildKit.Packaging/package.readme.targets
+++ b/manager/.toolkit/msbuild/DragoAnt.MSBuildKit.Packaging/package.readme.targets
@@ -3,7 +3,7 @@
   <!-- MSKit_PackageReadmeFrom: the package readme is generated from the repository README on pack,
        never on build. Relative links and images become absolute URLs pinned to the commit,
        nuget:skip / nuget:only blocks are applied, release and issue links are added to the overview.
-       The MSKIT_PKG checks then read the generated file. Full description: docs/package-readme.md. -->
+       The MSKITPKG checks then read the generated file. Full description: docs/package-readme.md. -->
 
   <PropertyGroup>
     <MSKit_PackageReadmeAllowedImageHostsFile Condition="'$(MSKit_PackageReadmeAllowedImageHostsFile)'==''">$(MSBuildThisFileDirectory)nuget.allowed-image-hosts.txt</MSKit_PackageReadmeAllowedImageHostsFile>
@@ -34,7 +34,7 @@
   <Target Name="_MSKit_PackageReadmeFromMissing"
           BeforeTargets="GenerateNuspec"
           Condition="'$(MSKit_PackageReadmeFrom)'!='' AND '$(_MSKit_GeneratesReadme)'!='True' AND '$(MSKit_SkipPackageChecks)'!='All'">
-    <Warning Code="MSKIT_PKG020" File="$(MSBuildProjectFullPath)"
+    <Warning Code="MSKITPKG020" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskitpkg020" File="$(MSBuildProjectFullPath)"
              Text="MSKit_PackageReadmeFrom names '$(MSKit_PackageReadmeFrom)', but $(_MSKit_ReadmeFromPath) does not exist, so no readme is generated for '$(PackageId)'. The path is relative to the git root ($(MSKit_GitRoot))." />
   </Target>
 
@@ -117,25 +117,25 @@
   <!-- The findings are kept beside the generated file, so an incremental pack still reports them. -->
   <Target Name="_MSKit_ReportPackageReadmeFindings" Condition="'$(MSKit_SkipPackageChecks)'!='All' AND '$(MSKit_SkipPackageChecks)'!='True'">
     <ItemGroup>
-      <_MSKit_ReadmeCode Include="MSKIT_PKG020;MSKIT_PKG021;MSKIT_PKG022" />
+      <_MSKit_ReadmeCode Include="MSKITPKG020;MSKITPKG021;MSKITPKG022" />
       <_MSKit_ReadmeSkip Include="$(MSKit_SkipPackageChecks);$(NoWarn)" />
       <_MSKit_ReadmeCode Remove="@(_MSKit_ReadmeSkip)" />
     </ItemGroup>
     <PropertyGroup>
       <_MSKit_ReadmeCodes>;@(_MSKit_ReadmeCode);</_MSKit_ReadmeCodes>
     </PropertyGroup>
-    <ReadLinesFromFile Condition="Exists('$(_MSKit_ReadmeFindingsBase).MSKIT_PKG020.txt') AND $(_MSKit_ReadmeCodes.Contains(';MSKIT_PKG020;'))" File="$(_MSKit_ReadmeFindingsBase).MSKIT_PKG020.txt">
+    <ReadLinesFromFile Condition="Exists('$(_MSKit_ReadmeFindingsBase).MSKITPKG020.txt') AND $(_MSKit_ReadmeCodes.Contains(';MSKITPKG020;'))" File="$(_MSKit_ReadmeFindingsBase).MSKITPKG020.txt">
       <Output TaskParameter="Lines" ItemName="_MSKit_ReadmeFinding020" />
     </ReadLinesFromFile>
-    <ReadLinesFromFile Condition="Exists('$(_MSKit_ReadmeFindingsBase).MSKIT_PKG021.txt') AND $(_MSKit_ReadmeCodes.Contains(';MSKIT_PKG021;'))" File="$(_MSKit_ReadmeFindingsBase).MSKIT_PKG021.txt">
+    <ReadLinesFromFile Condition="Exists('$(_MSKit_ReadmeFindingsBase).MSKITPKG021.txt') AND $(_MSKit_ReadmeCodes.Contains(';MSKITPKG021;'))" File="$(_MSKit_ReadmeFindingsBase).MSKITPKG021.txt">
       <Output TaskParameter="Lines" ItemName="_MSKit_ReadmeFinding021" />
     </ReadLinesFromFile>
-    <ReadLinesFromFile Condition="Exists('$(_MSKit_ReadmeFindingsBase).MSKIT_PKG022.txt') AND $(_MSKit_ReadmeCodes.Contains(';MSKIT_PKG022;'))" File="$(_MSKit_ReadmeFindingsBase).MSKIT_PKG022.txt">
+    <ReadLinesFromFile Condition="Exists('$(_MSKit_ReadmeFindingsBase).MSKITPKG022.txt') AND $(_MSKit_ReadmeCodes.Contains(';MSKITPKG022;'))" File="$(_MSKit_ReadmeFindingsBase).MSKITPKG022.txt">
       <Output TaskParameter="Lines" ItemName="_MSKit_ReadmeFinding022" />
     </ReadLinesFromFile>
-    <Warning Condition="'@(_MSKit_ReadmeFinding020)'!=''" Code="MSKIT_PKG020" File="$(_MSKit_ReadmeFromPath)" Text="%(_MSKit_ReadmeFinding020.Identity) (to skip: MSKit_SkipPackageChecks=MSKIT_PKG020)" />
-    <Warning Condition="'@(_MSKit_ReadmeFinding021)'!=''" Code="MSKIT_PKG021" File="$(_MSKit_ReadmeFromPath)" Text="%(_MSKit_ReadmeFinding021.Identity) (to skip: MSKit_SkipPackageChecks=MSKIT_PKG021)" />
-    <Warning Condition="'@(_MSKit_ReadmeFinding022)'!=''" Code="MSKIT_PKG022" File="$(_MSKit_ReadmeFromPath)" Text="%(_MSKit_ReadmeFinding022.Identity) (to skip: MSKit_SkipPackageChecks=MSKIT_PKG022)" />
+    <Warning Condition="'@(_MSKit_ReadmeFinding020)'!=''" Code="MSKITPKG020" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskitpkg020" File="$(_MSKit_ReadmeFromPath)" Text="%(_MSKit_ReadmeFinding020.Identity) (to skip: MSKit_SkipPackageChecks=MSKITPKG020)" />
+    <Warning Condition="'@(_MSKit_ReadmeFinding021)'!=''" Code="MSKITPKG021" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskitpkg021" File="$(_MSKit_ReadmeFromPath)" Text="%(_MSKit_ReadmeFinding021.Identity) (to skip: MSKit_SkipPackageChecks=MSKITPKG021)" />
+    <Warning Condition="'@(_MSKit_ReadmeFinding022)'!=''" Code="MSKITPKG022" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskitpkg022" File="$(_MSKit_ReadmeFromPath)" Text="%(_MSKit_ReadmeFinding022.Identity) (to skip: MSKit_SkipPackageChecks=MSKITPKG022)" />
   </Target>
 
 </Project>
diff --git a/manager/.toolkit/msbuild/DragoAnt.MSBuildKit.Packaging/package.targets b/manager/.toolkit/msbuild/DragoAnt.MSBuildKit.Packaging/package.targets
index 9b2c60d..b299d47 100644
--- a/manager/.toolkit/msbuild/DragoAnt.MSBuildKit.Packaging/package.targets
+++ b/manager/.toolkit/msbuild/DragoAnt.MSBuildKit.Packaging/package.targets
@@ -51,9 +51,9 @@
   </PropertyGroup>
 
   <!-- Icon: PackageIconPath (the kit's company layer points it at .toolkit/res/package.icon.png),
-       packed as icon.png. -->
+       packed as icon.<extension, lowercased> (icon.png, icon.jpg) unless the project sets PackageIcon. -->
   <PropertyGroup Condition="'$(PackageIcon)'=='' AND '$(PackageIconPath)'!='' AND Exists('$(PackageIconPath)')">
-    <PackageIcon>icon.png</PackageIcon>
+    <PackageIcon>icon$([System.IO.Path]::GetExtension('$(PackageIconPath)').ToLowerInvariant())</PackageIcon>
     <_MSKit_PacksIcon>True</_MSKit_PacksIcon>
   </PropertyGroup>
   <PropertyGroup>
@@ -63,7 +63,7 @@
 
   <ItemGroup>
     <None Condition="'$(_MSKit_PacksReadme)'=='True'" Include="$(MSKit_PackageReadmeSourcePath)" Pack="true" PackagePath="\$(PackageReadmeFile)" Visible="false" />
-    <None Condition="'$(_MSKit_PacksIcon)'=='True'" Include="$(PackageIconPath)" Pack="true" PackagePath="\icon.png" Visible="false" />
+    <None Condition="'$(_MSKit_PacksIcon)'=='True'" Include="$(PackageIconPath)" Pack="true" PackagePath="\$(PackageIcon)" Visible="false" />
 
     <None Include="build/**" PackagePath="build/" Pack="true" />
     <None Include="buildMultiTargeting/**" PackagePath="buildMultiTargeting/" Pack="true" />
diff --git a/manager/.toolkit/msbuild/DragoAnt.MSBuildKit.Packaging/package.tasks.cs.txt b/manager/.toolkit/msbuild/DragoAnt.MSBuildKit.Packaging/package.tasks.cs.txt
index d0d5ddf..4d3b6d5 100644
--- a/manager/.toolkit/msbuild/DragoAnt.MSBuildKit.Packaging/package.tasks.cs.txt
+++ b/manager/.toolkit/msbuild/DragoAnt.MSBuildKit.Packaging/package.tasks.cs.txt
@@ -31,7 +31,7 @@ public sealed class MSKit_PackageAssets : Task
     [Output] public string HtmlTags { get; set; }
     [Output] public string Alerts { get; set; }
     [Output] public bool HasMermaid { get; set; }
-    [Output] public bool IconIsPng { get; set; }
+    [Output] public string IconFormat { get; set; }
     [Output] public int IconWidth { get; set; }
     [Output] public int IconHeight { get; set; }
 
@@ -96,16 +96,18 @@ public sealed class MSKit_PackageAssets : Task
 
         if (!string.IsNullOrEmpty(IconPath) && File.Exists(IconPath))
         {
-            var header = new byte[24];
-            using (var stream = File.OpenRead(IconPath))
+            var icon = File.ReadAllBytes(IconPath);
+            IconFormat = "unknown";
+            if (icon.Length >= 24 && icon[0] == 0x89 && icon[1] == 0x50 && icon[2] == 0x4E && icon[3] == 0x47)
             {
-                var read = stream.Read(header, 0, header.Length);
-                IconIsPng = read == 24 && header[0] == 0x89 && header[1] == 0x50 && header[2] == 0x4E && header[3] == 0x47;
+                IconFormat = "PNG";
+                IconWidth = BigEndian(icon, 16, 4);
+                IconHeight = BigEndian(icon, 20, 4);
             }
-            if (IconIsPng)
+            else if (icon.Length >= 4 && icon[0] == 0xFF && icon[1] == 0xD8)
             {
-                IconWidth = (header[16] << 24) | (header[17] << 16) | (header[18] << 8) | header[19];
-                IconHeight = (header[20] << 24) | (header[21] << 16) | (header[22] << 8) | header[23];
+                IconFormat = "JPEG";
+                ReadJpegSize(icon);
             }
         }
 
@@ -116,6 +118,31 @@ public sealed class MSKit_PackageAssets : Task
         Alerts = string.Join(", ", alerts.Distinct());
     }
 
+    private static int BigEndian(byte[] bytes, int offset, int count)
+    {
+        var value = 0;
+        for (var i = 0; i < count; i++) value = (value << 8) | bytes[offset + i];
+        return value;
+    }
+
+    // Walks the JPEG segments to the first start-of-frame marker (SOF0..SOF15 except DHT, JPG, DAC).
+    private void ReadJpegSize(byte[] jpeg)
+    {
+        var i = 2;
+        while (i + 8 < jpeg.Length && jpeg[i] == 0xFF)
+        {
+            var marker = jpeg[i + 1];
+            if (marker == 0xFF) { i++; continue; }
+            if (marker >= 0xC0 && marker <= 0xCF && marker != 0xC4 && marker != 0xC8 && marker != 0xCC)
+            {
+                IconHeight = BigEndian(jpeg, i + 5, 2);
+                IconWidth = BigEndian(jpeg, i + 7, 2);
+                return;
+            }
+            i += 2 + BigEndian(jpeg, i + 2, 2);
+        }
+    }
+
     public string OutputPath { get; set; }
     public string FindingsBase { get; set; }
     public string ReleasesUrlPath { get; set; }
@@ -138,7 +165,7 @@ public sealed class MSKit_PackageAssets : Task
 
     private void GenerateReadme()
     {
-        var codes =new[] { "MSKIT_PKG020", "MSKIT_PKG021", "MSKIT_PKG022" };
+        var codes =new[] { "MSKITPKG020", "MSKITPKG021", "MSKITPKG022" };
         var findings = codes.ToDictionary(c => c, c => new List<string>());
         Action<string, string> report = (code, text) => findings[code].Add(text.Replace("\r", " ").Replace("\n", " "));
 
@@ -211,7 +238,7 @@ public sealed class MSKit_PackageAssets : Task
             case "":
                 break;
             default:
-                report("MSKIT_PKG020", display + ": MSKit_RepoProvider '" + provider + "' is not one of GitHub, GitLab, AzureDevOps, Bitbucket, Gitea; set MSKit_RepoBlobUrlTemplate and MSKit_RepoRawUrlTemplate instead.");
+                report("MSKITPKG020", display + ": MSKit_RepoProvider '" + provider + "' is not one of GitHub, GitLab, AzureDevOps, Bitbucket, Gitea; set MSKit_RepoBlobUrlTemplate and MSKit_RepoRawUrlTemplate instead.");
                 break;
         }
         if (norm(BlobTemplate).Length > 0) { blob = norm(BlobTemplate); tree = blob.Contains("/blob/") ? blob.Replace("/blob/", "/tree/") : blob; }
@@ -250,7 +277,7 @@ public sealed class MSKit_PackageAssets : Task
             if (!Uri.TryCreate(url.Trim('<', '>'), UriKind.Absolute, out u) || (u.Scheme != "https" && u.Scheme != "http")) return;
             var h = u.Host.ToLowerInvariant();
             if (allowed.Contains(h) || (h == "github.com" && Regex.IsMatch(u.AbsolutePath, @"^/[^/]+/[^/]+/(actions/)?workflows/[^/]+/badge\.svg$", RegexOptions.IgnoreCase))) return;
-            report("MSKIT_PKG021", display + " line " + n + ": the image " + url + " comes from " + h + ", a host nuget.org does not show images from. Use an allowed host (nuget.allowed-image-hosts.txt in the kit) or point MSKit_RepoRawUrlTemplate at one.");
+            report("MSKITPKG021", display + " line " + n + ": the image " + url + " comes from " + h + ", a host nuget.org does not show images from. Use an allowed host (nuget.allowed-image-hosts.txt in the kit) or point MSKit_RepoRawUrlTemplate at one.");
         };
 
         Func<string, bool, int, string> resolve = (target, isImage, n) =>
@@ -266,7 +293,7 @@ public sealed class MSKit_PackageAssets : Task
             var rp = combine(Uri.UnescapeDataString(p));
             if (rp == null)
             {
-                report("MSKIT_PKG020", display + " line " + n + ": " + t + " points outside the repository and is left as it is.");
+                report("MSKITPKG020", display + " line " + n + ": " + t + " points outside the repository and is left as it is.");
                 return target;
             }
             var isDir = Directory.Exists(Path.Combine(root, rp.Replace('/', Path.DirectorySeparatorChar)));
@@ -334,25 +361,25 @@ public sealed class MSKit_PackageAssets : Task
             }
             if (skipOpen.IsMatch(line))
             {
-                if (skipping) report("MSKIT_PKG020", display + " line " + n + ": nuget:skip opened again before line " + skipLine + "'s was closed.");
+                if (skipping) report("MSKITPKG020", display + " line " + n + ": nuget:skip opened again before line " + skipLine + "'s was closed.");
                 skipping = true; skipLine = n; continue;
             }
             if (skipClose.IsMatch(line))
             {
-                if (!skipping) report("MSKIT_PKG020", display + " line " + n + ": /nuget:skip has no matching nuget:skip.");
+                if (!skipping) report("MSKITPKG020", display + " line " + n + ": /nuget:skip has no matching nuget:skip.");
                 skipping = false; continue;
             }
             var om = onlyOpen.Match(line);
             if (om.Success)
             {
-                if (inOnly) report("MSKIT_PKG020", display + " line " + n + ": nuget:only opened again before line " + onlyLine + "'s was closed.");
+                if (inOnly) report("MSKITPKG020", display + " line " + n + ": nuget:only opened again before line " + onlyLine + "'s was closed.");
                 inOnly = true; onlyLine = n;
                 keepOnly = Regex.Split(om.Groups[1].Value.Trim(), @"[\s,]+").Any(id => string.Equals(id, PackageId, StringComparison.OrdinalIgnoreCase));
                 continue;
             }
             if (onlyClose.IsMatch(line))
             {
-                if (!inOnly) report("MSKIT_PKG020", display + " line " + n + ": /nuget:only has no matching nuget:only.");
+                if (!inOnly) report("MSKITPKG020", display + " line " + n + ": /nuget:only has no matching nuget:only.");
                 inOnly = false; keepOnly = true; continue;
             }
             var fm = fenceRe.Match(line);
@@ -366,10 +393,10 @@ public sealed class MSKit_PackageAssets : Task
             outLines.Add(rewriteLine(line, n));
             outFence.Add(false);
         }
-        if (skipping) report("MSKIT_PKG020", display + " line " + skipLine + ": nuget:skip is never closed, so everything after it is left out.");
-        if (inOnly) report("MSKIT_PKG020", display + " line " + onlyLine + ": nuget:only is never closed.");
+        if (skipping) report("MSKITPKG020", display + " line " + skipLine + ": nuget:skip is never closed, so everything after it is left out.");
+        if (inOnly) report("MSKITPKG020", display + " line " + onlyLine + ": nuget:only is never closed.");
         if (!canRewrite && unresolved > 0)
-            report("MSKIT_PKG020", display + ": " + unresolved + " relative link(s) and image(s) stay relative because " + why + ".");
+            report("MSKITPKG020", display + ": " + unresolved + " relative link(s) and image(s) stay relative because " + why + ".");
 
         var title = norm(ReadmeTitle) == "auto" ? norm(PackageId) : norm(ReadmeTitle);
         if (title.Length > 0)
@@ -422,7 +449,7 @@ public sealed class MSKit_PackageAssets : Task
 
         var visibility = norm(Visibility).ToLowerInvariant();
         if (visibility == "private" || visibility == "internal")
-            report("MSKIT_PKG022", "The repository " + (repoUrl.Length > 0 ? repoUrl : "of " + PackageId) + " is " + visibility + ": the links in the package readme of " + PackageId + " will not open for people reading it on nuget.org. Publish from a public repository, or point MSKit_RepoBlobUrlTemplate and MSKit_RepoRawUrlTemplate at a public mirror.");
+            report("MSKITPKG022", "The repository " + (repoUrl.Length > 0 ? repoUrl : "of " + PackageId) + " is " + visibility + ": the links in the package readme of " + PackageId + " will not open for people reading it on nuget.org. Publish from a public repository, or point MSKit_RepoBlobUrlTemplate and MSKit_RepoRawUrlTemplate at a public mirror.");
 
         var result = new List<string>();
         var blank = true;
diff --git a/manager/.toolkit/msbuild/DragoAnt.MSBuildKit.Testing.XUnit.v3/audit/audit.tests.project.xunit.v3.targets b/manager/.toolkit/msbuild/DragoAnt.MSBuildKit.Testing.XUnit.v3/audit/audit.tests.project.xunit.v3.targets
index febe8d5..adb4177 100644
--- a/manager/.toolkit/msbuild/DragoAnt.MSBuildKit.Testing.XUnit.v3/audit/audit.tests.project.xunit.v3.targets
+++ b/manager/.toolkit/msbuild/DragoAnt.MSBuildKit.Testing.XUnit.v3/audit/audit.tests.project.xunit.v3.targets
@@ -1,13 +1,13 @@
 <Project>
 
-  <!-- MSKIT_TEST005: xunit.v3 needs net8.0 or later. -->
+  <!-- MSKITTEST005: xunit.v3 needs net8.0 or later. -->
   <Target Name="ValidateXUnitV3TFM"
           BeforeTargets="Build"
           Condition="'$(IsTestsProject)'=='True'
                       AND '$(MSKit_TestingFramework)'=='xunit.v3'
                       AND '$(TargetFramework)'!=''
                       AND '$(IsNET8_OR_GREATER)'!='True'">
-    <Error Code="MSKIT_TEST005"
+    <Error Code="MSKITTEST005" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskittest005"
            File="$(MSBuildProjectFullPath)"
            Text="MSKit_TestingFramework='xunit.v3' requires net8.0 or later. Current target framework: $(TargetFramework).%0AFix: target net8.0 or later in the test project." />
   </Target>
diff --git a/manager/.toolkit/msbuild/DragoAnt.MSBuildKit.Testing/audit/audit.internalsVisibleTo.targets b/manager/.toolkit/msbuild/DragoAnt.MSBuildKit.Testing/audit/audit.internalsVisibleTo.targets
index 8de8fe0..3164d5b 100644
--- a/manager/.toolkit/msbuild/DragoAnt.MSBuildKit.Testing/audit/audit.internalsVisibleTo.targets
+++ b/manager/.toolkit/msbuild/DragoAnt.MSBuildKit.Testing/audit/audit.internalsVisibleTo.targets
@@ -4,7 +4,7 @@
 
   <!-- Gated like test.project.internalsVisibleTo.targets: only non-test projects emit InternalsVisibleTo. -->
   <Target Name="ValidateMSKitTestsDirSet" BeforeTargets="BeforeCompile" Condition="'$(InternalsVisibleToAllTestsProjects)'=='True'">
-    <Warning Code="MSKIT_TEST030" Condition="'$(MSKit_TestsDir)'==''"
+    <Warning Code="MSKITTEST030" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskittest030" Condition="'$(MSKit_TestsDir)'==''"
              Text="MSKit_TestsDir is empty — cannot auto-emit InternalsVisibleTo for sibling .Tests projects.%0AFix: set MSKit_TestsDir in Directory.Build.props:%0A  &lt;PropertyGroup&gt;%0A    &lt;MSKit_TestsDir&gt;$(MSBuildThisFileDirectory)tests&lt;/MSKit_TestsDir&gt;%0A  &lt;/PropertyGroup&gt;%0ATo disable auto InternalsVisibleTo, add to csproj:%0A  &lt;PropertyGroup&gt;%0A    &lt;InternalsVisibleToAllTestsProjects&gt;False&lt;/InternalsVisibleToAllTestsProjects&gt;%0A  &lt;/PropertyGroup&gt;"
              File="$(MSBuildProjectFullPath)" />
   </Target>
@@ -12,7 +12,7 @@
   <!-- Warn when MSKit_TestsDir points to a non-existent directory.
        Gate: InternalsVisibleToAllTestsProjects==True — see ValidateMSKitTestsDirSet for rationale. -->
   <Target Name="ValidateMSKitTestsDirExists" BeforeTargets="BeforeCompile" Condition="'$(InternalsVisibleToAllTestsProjects)'=='True'">
-    <Warning Code="MSKIT_TEST031" Condition="'$(MSKit_TestsDir)'!='' And !Exists('$(MSKit_TestsDir)')"
+    <Warning Code="MSKITTEST031" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskittest031" Condition="'$(MSKit_TestsDir)'!='' And !Exists('$(MSKit_TestsDir)')"
              Text="MSKit_TestsDir='$(MSKit_TestsDir)' does not exist.%0AFix: point MSKit_TestsDir to an existing directory in Directory.Build.props:%0A  &lt;PropertyGroup&gt;%0A    &lt;MSKit_TestsDir&gt;$(MSBuildThisFileDirectory)tests&lt;/MSKit_TestsDir&gt;%0A  &lt;/PropertyGroup&gt;%0ATo disable auto InternalsVisibleTo, add to csproj:%0A  &lt;PropertyGroup&gt;%0A    &lt;InternalsVisibleToAllTestsProjects&gt;False&lt;/InternalsVisibleToAllTestsProjects&gt;%0A  &lt;/PropertyGroup&gt;"
              File="$(MSBuildProjectFullPath)" />
   </Target>
diff --git a/manager/.toolkit/msbuild/DragoAnt.MSBuildKit.Testing/audit/audit.tests.lib.project.targets b/manager/.toolkit/msbuild/DragoAnt.MSBuildKit.Testing/audit/audit.tests.lib.project.targets
index 11cb07e..0d8e18e 100644
--- a/manager/.toolkit/msbuild/DragoAnt.MSBuildKit.Testing/audit/audit.tests.lib.project.targets
+++ b/manager/.toolkit/msbuild/DragoAnt.MSBuildKit.Testing/audit/audit.tests.lib.project.targets
@@ -1,35 +1,35 @@
 <Project>
 
-  <!-- Test helper library checks, MSKIT_TEST020..022. A test helper library may also set IsTestsLibProject directly: everything it needs is wired in the targets phase. -->
+  <!-- Test helper library checks, MSKITTEST020..022. A test helper library may also set IsTestsLibProject directly: everything it needs is wired in the targets phase. -->
 
-  <!-- MSKIT_TEST020: MSKit_TestingFramework must be set BEFORE LibCommonProps Import -->
+  <!-- MSKITTEST020: MSKit_TestingFramework must be set BEFORE LibCommonProps Import -->
   <Target Name="ValidateTestingFrameworkSetBeforeLibCommonPropsImport"
           BeforeTargets="CoreCompile;Build"
           Condition="'$(_MSKit_TestsLibProjectCommonPropsImported)'=='True'
                       AND '$(_MSKit_TestingFrameworkAtLibCommonPropsImport)'==''">
-    <Error Code="MSKIT_TEST020"
+    <Error Code="MSKITTEST020" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskittest020"
            File="$(MSBuildProjectFullPath)"
            Text="MSKit_TestingFramework was not set when $(TestsLibProjectCommonPropsPath) was imported.%0AFix: set the framework PropertyGroup BEFORE the Import:%0A  &lt;PropertyGroup&gt;%0A    &lt;MSKit_TestingFramework&gt;xunit.v3&lt;/MSKit_TestingFramework&gt;%0A  &lt;/PropertyGroup&gt;%0A  &lt;Import Project=&quot;$(TestsLibProjectCommonPropsPath)&quot; /&gt;" />
   </Target>
 
-  <!-- MSKIT_TEST021: framework changed after the Lib Import -->
+  <!-- MSKITTEST021: framework changed after the Lib Import -->
   <Target Name="ValidateTestingFrameworkUnchangedSinceLibImport"
           BeforeTargets="CoreCompile;Build"
           Condition="'$(_MSKit_TestsLibProjectCommonPropsImported)'=='True'
                       AND '$(_MSKit_TestingFrameworkAtLibCommonPropsImport)'!=''
                       AND '$(_MSKit_TestingFrameworkAtLibCommonPropsImport)'!='$(MSKit_TestingFramework)'">
-    <Error Code="MSKIT_TEST021"
+    <Error Code="MSKITTEST021" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskittest021"
            File="$(MSBuildProjectFullPath)"
            Text="MSKit_TestingFramework changed after $(TestsLibProjectCommonPropsPath) was imported.%0AAt import: '$(_MSKit_TestingFrameworkAtLibCommonPropsImport)'   csproj-final: '$(MSKit_TestingFramework)'.%0AFix: move the framework PropertyGroup ABOVE the Import." />
   </Target>
 
-  <!-- MSKIT_TEST022: no satellite or custom LibCommonProps path resolved -->
+  <!-- MSKITTEST022: no satellite or custom LibCommonProps path resolved -->
   <Target Name="ValidateTestingFrameworkLibCommonPropsPathResolved"
           BeforeTargets="CoreCompile;Build"
           Condition="'$(_MSKit_TestsLibProjectCommonPropsImported)'=='True'
                       AND '$(MSKit_TestingFramework_LibCommonPropsPath)'==''
                       AND '$(MSKit_TestingFramework)'!=''">
-    <Error Code="MSKIT_TEST022"
+    <Error Code="MSKITTEST022" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskittest022"
            File="$(MSBuildProjectFullPath)"
            Text="No LibCommonProps path resolved for MSKit_TestingFramework='$(MSKit_TestingFramework)'.%0AFix: use a framework the kit ships (xunit.v3) or set MSKit_TestingFramework_LibCommonPropsPath to a custom file." />
   </Target>
diff --git a/manager/.toolkit/msbuild/DragoAnt.MSBuildKit.Testing/audit/audit.tests.project.targets b/manager/.toolkit/msbuild/DragoAnt.MSBuildKit.Testing/audit/audit.tests.project.targets
index 8075de2..5035f83 100644
--- a/manager/.toolkit/msbuild/DragoAnt.MSBuildKit.Testing/audit/audit.tests.project.targets
+++ b/manager/.toolkit/msbuild/DragoAnt.MSBuildKit.Testing/audit/audit.tests.project.targets
@@ -1,13 +1,13 @@
 <Project>
 
-  <!-- Runnable-test-project checks, MSKIT_TEST010..026. BeforeTargets includes CoreCompile so they
+  <!-- Runnable-test-project checks, MSKITTEST010..026. BeforeTargets includes CoreCompile so they
        fire before generated entry-point code can mask them with compiler errors. -->
 
   <Target Name="ValidateTestingFrameworkSetBeforeCommonPropsImport"
           BeforeTargets="CoreCompile;Build"
           Condition="'$(_MSKit_TestsProjectCommonPropsImported)'=='True'
                       AND '$(_MSKit_TestingFrameworkAtCommonPropsImport)'==''">
-    <Error Code="MSKIT_TEST010"
+    <Error Code="MSKITTEST010" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskittest010"
            File="$(MSBuildProjectFullPath)"
            Text="MSKit_TestingFramework was not set when $(TestsProjectCommonPropsPath) was imported.%0AFix: set it BEFORE the Import:%0A  &lt;PropertyGroup&gt;%0A    &lt;MSKit_TestingFramework&gt;xunit.v3&lt;/MSKit_TestingFramework&gt;%0A  &lt;/PropertyGroup&gt;%0A  &lt;Import Project=&quot;$(TestsProjectCommonPropsPath)&quot; /&gt;" />
   </Target>
@@ -17,7 +17,7 @@
           Condition="'$(_MSKit_TestsProjectCommonPropsImported)'=='True'
                       AND '$(_MSKit_TestingFrameworkAtCommonPropsImport)'!=''
                       AND '$(_MSKit_TestingFrameworkAtCommonPropsImport)'!='$(MSKit_TestingFramework)'">
-    <Error Code="MSKIT_TEST011"
+    <Error Code="MSKITTEST011" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskittest011"
            File="$(MSBuildProjectFullPath)"
            Text="MSKit_TestingFramework changed after $(TestsProjectCommonPropsPath) was imported (at import: '$(_MSKit_TestingFrameworkAtCommonPropsImport)', final: '$(MSKit_TestingFramework)').%0AFix: move the framework PropertyGroup above the Import." />
   </Target>
@@ -27,12 +27,12 @@
           Condition="'$(_MSKit_TestsProjectCommonPropsImported)'=='True'
                       AND '$(MSKit_TestingFramework_CommonPropsPath)'==''
                       AND '$(MSKit_TestingFramework)'!=''">
-    <Error Code="MSKIT_TEST012"
+    <Error Code="MSKITTEST012" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskittest012"
            File="$(MSBuildProjectFullPath)"
            Text="No framework wiring found for MSKit_TestingFramework='$(MSKit_TestingFramework)'.%0AFix: use a framework the kit ships (xunit.v3), or point MSKit_TestingFramework_CommonPropsPath at your own props file." />
   </Target>
 
-  <!-- MSKIT_TEST013 reads the csproj text, comments stripped, so a direct declaration is caught
+  <!-- MSKITTEST013 reads the csproj text, comments stripped, so a direct declaration is caught
        even when the name would also match auto-detect. -->
   <Target Name="ValidateIsTestsProjectNotSetDirectly"
           BeforeTargets="CoreCompile;Build"
@@ -44,7 +44,7 @@
       <_MSKit_CsprojText013>$([System.Text.RegularExpressions.Regex]::Replace($(_MSKit_CsprojText013), '&lt;!--[\s\S]*?--&gt;', ''))</_MSKit_CsprojText013>
       <_MSKit_HasDirectIsTestsProject>$([System.Text.RegularExpressions.Regex]::IsMatch($(_MSKit_CsprojText013), '&lt;IsTestsProject\s*&gt;'))</_MSKit_HasDirectIsTestsProject>
     </PropertyGroup>
-    <Error Code="MSKIT_TEST013"
+    <Error Code="MSKITTEST013" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskittest013"
            File="$(MSBuildProjectFullPath)"
            Condition="'$(_MSKit_HasDirectIsTestsProject)'=='True'"
            Text="csproj '$(MSBuildProjectName)' declares &lt;IsTestsProject&gt; directly. That is set too late for the Microsoft.Testing.Platform wiring, which happens in the props phase.%0AFix: rename the project to match MSKit_TestsProjectNameRegex (default: names ending in .Tests), or replace the property with the explicit endpoint:%0A  &lt;PropertyGroup&gt;%0A    &lt;MSKit_TestingFramework&gt;xunit.v3&lt;/MSKit_TestingFramework&gt;%0A  &lt;/PropertyGroup&gt;%0A  &lt;Import Project=&quot;$(TestsProjectCommonPropsPath)&quot; /&gt;" />
@@ -55,7 +55,7 @@
           Condition="'$(MSKit_IsTestsProjectAutoDetected)'=='True'
                       AND ('$(IsTestsLibProject)'=='True' OR '$(_MSKit_TestsLibProjectCommonPropsImported)'=='True')
                       AND '$(MSKit_IsTestsLibProjectAutoDetected)'!='True'">
-    <Error Code="MSKIT_TEST014"
+    <Error Code="MSKITTEST014" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskittest014"
            File="$(MSBuildProjectFullPath)"
            Text="Project name '$(MSBuildProjectName)' matches the tests auto-detect regex '$(_MSKit_TestsProjectNameRegex_Shared)' but the project is marked as a test helper library. A project cannot be both.%0AFix one of:%0A  1. Rename the project so it no longer matches (e.g. 'Foo.Tests' to 'Foo.TestUtils')%0A  2. Override MSKit_TestsProjectNameRegex in Directory.Build.props%0A  3. Drop the IsTestsLibProject flag if this is a runnable test project" />
   </Target>
@@ -65,7 +65,7 @@
           Condition="('$(IsTestsProject)'=='True' OR '$(IsTestsLibProject)'=='True')
                       AND '$(MSKit_TestingFramework)'!=''
                       AND '$(MSKit_TestingFrameworkAttached)'!='true'">
-    <Error Code="MSKIT_TEST026"
+    <Error Code="MSKITTEST026" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskittest026"
            File="$(MSBuildProjectFullPath)"
            Text="Project '$(MSBuildProjectName)' has MSKit_TestingFramework='$(MSKit_TestingFramework)' but no installed kit part wires that framework.%0AFix: use xunit.v3 (part DragoAnt.MSBuildKit.Testing.XUnit.v3), or set MSKit_TestingFramework_CommonPropsPath to your own wiring." />
   </Target>
@@ -74,7 +74,7 @@
           BeforeTargets="CoreCompile;Build"
           Condition="('$(IsTestsProject)'=='True' OR '$(IsTestsLibProject)'=='True')
                       AND '$(MSKit_TestingFramework)'==''">
-    <Error Code="MSKIT_TEST025"
+    <Error Code="MSKITTEST025" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskittest025"
            File="$(MSBuildProjectFullPath)"
            Text="Project '$(MSBuildProjectName)' is a test project but MSKit_TestingFramework is not set.%0AFix: add to Directory.Build.props:%0A  &lt;MSKit_TestingFramework&gt;xunit.v3&lt;/MSKit_TestingFramework&gt;" />
   </Target>
diff --git a/manager/.toolkit/msbuild/DragoAnt.MSBuildKit.Testing/tests.lib.project.common.props b/manager/.toolkit/msbuild/DragoAnt.MSBuildKit.Testing/tests.lib.project.common.props
index 9685d6b..e280c2f 100644
--- a/manager/.toolkit/msbuild/DragoAnt.MSBuildKit.Testing/tests.lib.project.common.props
+++ b/manager/.toolkit/msbuild/DragoAnt.MSBuildKit.Testing/tests.lib.project.common.props
@@ -1,7 +1,7 @@
 <Project>
 
   <!-- Explicit endpoint for a test helper library. Set MSKit_TestingFramework before the import
-       (MSKIT_TEST020 checks it). -->
+       (MSKITTEST020 checks it). -->
   <PropertyGroup>
     <_MSKit_TestingFrameworkAtLibCommonPropsImport>$(MSKit_TestingFramework)</_MSKit_TestingFrameworkAtLibCommonPropsImport>
     <_MSKit_TestsLibProjectCommonPropsImported>True</_MSKit_TestsLibProjectCommonPropsImported>
diff --git a/manager/.toolkit/msbuild/DragoAnt.MSBuildKit.Testing/tests.project.common.props b/manager/.toolkit/msbuild/DragoAnt.MSBuildKit.Testing/tests.project.common.props
index 72b358c..bc9dfbb 100644
--- a/manager/.toolkit/msbuild/DragoAnt.MSBuildKit.Testing/tests.project.common.props
+++ b/manager/.toolkit/msbuild/DragoAnt.MSBuildKit.Testing/tests.project.common.props
@@ -1,7 +1,7 @@
 <Project>
 
   <!-- Explicit endpoint for a runnable test project whose name the auto-detect regex does not
-       match. Set MSKit_TestingFramework before the import (MSKIT_TEST010 checks it). -->
+       match. Set MSKit_TestingFramework before the import (MSKITTEST010 checks it). -->
   <PropertyGroup>
     <_MSKit_TestingFrameworkAtCommonPropsImport>$(MSKit_TestingFramework)</_MSKit_TestingFrameworkAtCommonPropsImport>
     <_MSKit_TestsProjectCommonPropsImported>True</_MSKit_TestsProjectCommonPropsImported>
diff --git a/manager/.toolkit/msbuild/DragoAnt.MSBuildKit/audit/audit.implicit.packages.duplicates.targets b/manager/.toolkit/msbuild/DragoAnt.MSBuildKit/audit/audit.implicit.packages.duplicates.targets
index b03a750..225b9e6 100644
--- a/manager/.toolkit/msbuild/DragoAnt.MSBuildKit/audit/audit.implicit.packages.duplicates.targets
+++ b/manager/.toolkit/msbuild/DragoAnt.MSBuildKit/audit/audit.implicit.packages.duplicates.targets
@@ -1,6 +1,6 @@
 <Project>
 
-  <!-- MSKIT_DUP001: Directory.Packages.props declares a <PackageVersion> the kit already declares
+  <!-- MSKITDUP001: Directory.Packages.props declares a <PackageVersion> the kit already declares
        (the kit's items carry ControlledBy metadata). NuGet would otherwise report NU1506 and pick
        one silently. MSKit_SkipAudit_ImplicitPackageDuplicates=True bypasses the check. -->
 
@@ -25,7 +25,7 @@
                                          AND $(_MSKit_ConsumerIdsStr.Contains(';%(PackageVersion.Identity);'))" />
     </ItemGroup>
 
-    <Error Code="MSKIT_DUP001"
+    <Error Code="MSKITDUP001" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskitdup001"
            Condition=" '@(_MSKit_DuplicateReport)' != '' "
            Text="Directory.Packages.props declares &lt;PackageVersion&gt; entries the kit already provides:%0A%0A@(_MSKit_DuplicateReport->'  %(Identity)  &#x2190; provided by %(ControlledBy)','%0A')%0A%0AFix: remove those &lt;PackageVersion Include=&quot;...&quot; /&gt; lines. To pin another version, set the kit's version property instead (for example &lt;MSKit_PackageVersion_XunitV3&gt;), or turn the kit's versions off with &lt;MSKit_ImplicitPackageVersions&gt;False&lt;/MSKit_ImplicitPackageVersions&gt;.%0ATo bypass this check: &lt;MSKit_SkipAudit_ImplicitPackageDuplicates&gt;True&lt;/MSKit_SkipAudit_ImplicitPackageDuplicates&gt;"
            File="$(MSBuildProjectFullPath)" />
diff --git a/manager/.toolkit/msbuild/DragoAnt.MSBuildKit/audit/audit.prerelease.packages.targets b/manager/.toolkit/msbuild/DragoAnt.MSBuildKit/audit/audit.prerelease.packages.targets
index 534e94f..e84b7bf 100644
--- a/manager/.toolkit/msbuild/DragoAnt.MSBuildKit/audit/audit.prerelease.packages.targets
+++ b/manager/.toolkit/msbuild/DragoAnt.MSBuildKit/audit/audit.prerelease.packages.targets
@@ -1,6 +1,6 @@
 <Project>
 
-  <!-- MSKIT_PRE001: a stable-branch build references a prerelease version of one of your own
+  <!-- MSKITPRE001: a stable-branch build references a prerelease version of one of your own
        packages (ids starting with MSKit_PrereleasePackagePrefix). Warning by default;
        MSKit_PrereleasePackageCheckAsWarning=false makes it an error. -->
 
@@ -18,10 +18,10 @@
     <PropertyGroup>
       <_MSKit_PrereleaseText>Prerelease $(MSKit_PrereleasePackagePrefix)* packages referenced on stable branch '$(MSKit_Branch)':%0A@(_MSKit_PrereleaseReferences->'  %(Identity) %(Version)', '%0A')%0AFix: replace them with stable versions in Directory.Packages.props or the csproj.</_MSKit_PrereleaseText>
     </PropertyGroup>
-    <Warning Code="MSKIT_PRE001"
+    <Warning Code="MSKITPRE001" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskitpre001"
              Condition="'@(_MSKit_PrereleaseReferences)'!='' AND '$(MSKit_PrereleasePackageCheckAsWarning)'=='true'"
              Text="$(_MSKit_PrereleaseText)" />
-    <Error Code="MSKIT_PRE001"
+    <Error Code="MSKITPRE001" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskitpre001"
            Condition="'@(_MSKit_PrereleaseReferences)'!='' AND '$(MSKit_PrereleasePackageCheckAsWarning)'!='true'"
            Text="$(_MSKit_PrereleaseText)" />
   </Target>
diff --git a/manager/.toolkit/msbuild/DragoAnt.MSBuildKit/audit/audit.restrict.packages.targets b/manager/.toolkit/msbuild/DragoAnt.MSBuildKit/audit/audit.restrict.packages.targets
index 4fba85c..f1ad97e 100644
--- a/manager/.toolkit/msbuild/DragoAnt.MSBuildKit/audit/audit.restrict.packages.targets
+++ b/manager/.toolkit/msbuild/DragoAnt.MSBuildKit/audit/audit.restrict.packages.targets
@@ -1,6 +1,6 @@
 <Project InitialTargets="RestrictPackageReferenceAudit">
 
-  <!-- MSKIT_RES001 / MSKIT_RES002: a referenced package is banned (Type="Error") or discouraged
+  <!-- MSKITRES001 / MSKITRES002: a referenced package is banned (Type="Error") or discouraged
        (Type="Warning") by an MSKit_RestrictPackageReference item:
          <MSKit_RestrictPackageReference Include="Moq" Type="Error" Message="Use NSubstitute." />
        SkipGlobalRestriction="True" on one PackageReference downgrades it to a warning. -->
@@ -13,17 +13,17 @@
                                         SkipGlobalRestriction="True" />
     </ItemGroup>
 
-    <Error Code="MSKIT_RES001"
+    <Error Code="MSKITRES001" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskitres001"
       Condition="'%(MSKit_PackageReferenceNotAllowed.Identity)'!='' And '%(MSKit_PackageReferenceNotAllowed.Type)'=='Error' And '%(MSKit_PackageReferenceNotAllowed.SkipGlobalRestriction)'!='True'"
       Text="Package '%(MSKit_PackageReferenceNotAllowed.Identity)' is prohibited. %(MSKit_PackageReferenceNotAllowed.Message)%0AFix: remove the PackageReference or use the suggested alternative. To allow this one reference, add SkipGlobalRestriction=&quot;True&quot; to it."
       File="$(MSBuildProjectFullPath)" />
 
-    <Warning Code="MSKIT_RES001"
+    <Warning Code="MSKITRES001" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskitres001"
       Condition="'%(MSKit_PackageReferenceNotAllowed.Identity)'!='' And '%(MSKit_PackageReferenceNotAllowed.Type)'=='Error' And '%(MSKit_PackageReferenceNotAllowed.SkipGlobalRestriction)'=='True'"
       Text="Package '%(MSKit_PackageReferenceNotAllowed.Identity)' is prohibited (allowed here by SkipGlobalRestriction). %(MSKit_PackageReferenceNotAllowed.Message)"
       File="$(MSBuildProjectFullPath)" />
 
-    <Warning Code="MSKIT_RES002"
+    <Warning Code="MSKITRES002" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskitres002"
       Condition="'%(MSKit_PackageReferenceNotAllowed.Identity)'!='' And '%(MSKit_PackageReferenceNotAllowed.Type)'=='Warning' And '%(MSKit_PackageReferenceNotAllowed.SkipGlobalRestriction)'!='True'"
       Text="Package '%(MSKit_PackageReferenceNotAllowed.Identity)' is discouraged. %(MSKit_PackageReferenceNotAllowed.Message)%0ATo silence this for one reference, add SkipGlobalRestriction=&quot;True&quot; to it."
       File="$(MSBuildProjectFullPath)" />
diff --git a/manager/.toolkit/msbuild/DragoAnt.MSBuildKit/audit/audit.restrict.reference.targets b/manager/.toolkit/msbuild/DragoAnt.MSBuildKit/audit/audit.restrict.reference.targets
index 6e84fa3..462ab83 100644
--- a/manager/.toolkit/msbuild/DragoAnt.MSBuildKit/audit/audit.restrict.reference.targets
+++ b/manager/.toolkit/msbuild/DragoAnt.MSBuildKit/audit/audit.restrict.reference.targets
@@ -1,6 +1,6 @@
 <Project InitialTargets="RestrictProjectReferenceAudit;RestrictAllowedPackageReferenceAudit">
 
-  <!-- MSKIT_RES003 / MSKIT_RES004: allow-list mode. With MSKit_RestrictProjectReferences=True
+  <!-- MSKITRES003 / MSKITRES004: allow-list mode. With MSKit_RestrictProjectReferences=True
        (or MSKit_RestrictPackageReferences=True, or MSKit_RestrictReferences=True for both), every
        reference must carry Allowed="True". -->
 
@@ -15,7 +15,7 @@
       <MSKit_ProjectReferenceNotAllowed Include="@(ProjectReference)"
                                         Condition=" '%(ProjectReference.Allowed)'!='True' AND '@(ProjectReference)'!='' AND '%(Identity)'!=''" />
     </ItemGroup>
-    <Error Code="MSKIT_RES003"
+    <Error Code="MSKITRES003" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskitres003"
            Condition="'%(MSKit_ProjectReferenceNotAllowed.Identity)'!=''"
            Text="ProjectReference '%(MSKit_ProjectReferenceNotAllowed.Identity)' is not allowed in this project.%0AFix: remove it, or mark it allowed: &lt;ProjectReference Include=&quot;%(MSKit_ProjectReferenceNotAllowed.Identity)&quot; Allowed=&quot;True&quot; /&gt;"
            File="$(MSBuildProjectFullPath)" />
@@ -26,7 +26,7 @@
       <_MSKit_PackageReferenceNotAllowListed Include="@(PackageReference)"
                                              Condition=" '%(PackageReference.Allowed)'!='True' AND '@(PackageReference)'!='' AND '%(Identity)'!=''" />
     </ItemGroup>
-    <Error Code="MSKIT_RES004"
+    <Error Code="MSKITRES004" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskitres004"
            Condition="'%(_MSKit_PackageReferenceNotAllowListed.Identity)'!=''"
            Text="PackageReference '%(_MSKit_PackageReferenceNotAllowListed.Identity)' is not allowed in this project.%0AFix: remove it, or mark it allowed: &lt;PackageReference Include=&quot;%(_MSKit_PackageReferenceNotAllowListed.Identity)&quot; Allowed=&quot;True&quot; /&gt;"
            File="$(MSBuildProjectFullPath)" />
diff --git a/manager/.toolkit/msbuild/DragoAnt.MSBuildKit/audit/audit.shared.properties.targets b/manager/.toolkit/msbuild/DragoAnt.MSBuildKit/audit/audit.shared.properties.targets
index eeda662..d86f043 100644
--- a/manager/.toolkit/msbuild/DragoAnt.MSBuildKit/audit/audit.shared.properties.targets
+++ b/manager/.toolkit/msbuild/DragoAnt.MSBuildKit/audit/audit.shared.properties.targets
@@ -30,29 +30,29 @@
       <_MSKit_TFs_ProjNodeCount>@(_MSKit_TFs_NodeCheckXmlResult-&gt;Count())</_MSKit_TFs_ProjNodeCount>
     </PropertyGroup>
 
-    <!-- MSKIT_SHARED006: csproj <TargetFramework> declares the SAME value as the shared config.
+    <!-- MSKITSHARED006: csproj <TargetFramework> declares the SAME value as the shared config.
          Pure literal duplicate; not bypassable. Reads MSKit_TargetFramework_Proj (set by Core
          tfm.routine.props at props phase). -->
-    <Error Code="MSKIT_SHARED006"
+    <Error Code="MSKITSHARED006" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskitshared006"
            Condition="'$(MSKit_TargetFramework_Proj)'!=''
                       AND '$(MSKit_TargetFramework_Shared)'!=''
                       AND '$(MSKit_TargetFramework_Proj)'=='$(MSKit_TargetFramework_Shared)'"
            File="$(MSBuildProjectFullPath)"
            Text="csproj '$(MSBuildProjectName)' declares &lt;TargetFramework&gt;$(MSKit_TargetFramework_Proj)&lt;/TargetFramework&gt; which equals Directory.Build.props's &lt;TargetFramework&gt;$(MSKit_TargetFramework_Shared)&lt;/TargetFramework&gt; - the csproj declaration is redundant.%0AFix: remove this from the csproj &lt;PropertyGroup&gt;:%0A  &lt;TargetFramework&gt;$(MSKit_TargetFramework_Proj)&lt;/TargetFramework&gt;%0ADirectory.Build.props is the single source of truth.%0AThis check is not bypassable; pure literal duplication is always a code smell." />
 
-    <!-- MSKIT_SHARED007: csproj <TargetFrameworks> declares the SAME value as the shared config.
+    <!-- MSKITSHARED007: csproj <TargetFrameworks> declares the SAME value as the shared config.
          Pure literal duplicate; not bypassable. -->
-    <Error Code="MSKIT_SHARED007"
+    <Error Code="MSKITSHARED007" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskitshared007"
            Condition="'$(MSKit_TargetFrameworks_Proj)'!=''
                       AND '$(MSKit_TargetFrameworks_Shared)'!=''
                       AND '$(MSKit_TargetFrameworks_Proj)'=='$(MSKit_TargetFrameworks_Shared)'"
            File="$(MSBuildProjectFullPath)"
            Text="csproj '$(MSBuildProjectName)' declares &lt;TargetFrameworks&gt;$(MSKit_TargetFrameworks_Proj)&lt;/TargetFrameworks&gt; which equals Directory.Build.props's &lt;TargetFrameworks&gt;$(MSKit_TargetFrameworks_Shared)&lt;/TargetFrameworks&gt; - the csproj declaration is redundant.%0AFix: remove this from the csproj &lt;PropertyGroup&gt;:%0A  &lt;TargetFrameworks&gt;$(MSKit_TargetFrameworks_Proj)&lt;/TargetFrameworks&gt;%0ADirectory.Build.props is the single source of truth.%0AThis check is not bypassable; pure literal duplication is always a code smell." />
 
-    <!-- MSKIT_SHARED008: csproj <TargetFramework> overrides DBP's <TargetFramework> with a different value.
+    <!-- MSKITSHARED008: csproj <TargetFramework> overrides DBP's <TargetFramework> with a different value.
          Warning by default; bypass with MSKit_SkipAudit_TargetFrameworkOverride=True.
          Does not fire when the csproj switches shape. -->
-    <Warning Code="MSKIT_SHARED008"
+    <Warning Code="MSKITSHARED008" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskitshared008"
              Condition="'$(MSKit_SkipAudit_TargetFrameworkOverride)'!='True'
                         AND '$(MSKit_TargetFramework_Proj)'!=''
                         AND '$(MSKit_TargetFramework_Shared)'!=''
@@ -61,10 +61,10 @@
              File="$(MSBuildProjectFullPath)"
              Text="csproj '$(MSBuildProjectName)' declares &lt;TargetFramework&gt;$(MSKit_TargetFramework_Proj)&lt;/TargetFramework&gt; but Directory.Build.props centralizes &lt;TargetFramework&gt;$(MSKit_TargetFramework_Shared)&lt;/TargetFramework&gt; as the default.%0ARecommended: remove the csproj-level &lt;TargetFramework&gt; declaration (DBP is the single source of truth).%0ATo override intentionally, add to the csproj &lt;PropertyGroup&gt;:%0A  &lt;MSKit_SkipAudit_TargetFrameworkOverride&gt;True&lt;/MSKit_SkipAudit_TargetFrameworkOverride&gt;" />
 
-    <!-- MSKIT_SHARED009: csproj <TargetFrameworks> overrides DBP's <TargetFrameworks> with a different value.
+    <!-- MSKITSHARED009: csproj <TargetFrameworks> overrides DBP's <TargetFrameworks> with a different value.
          Warning by default; bypass with MSKit_SkipAudit_TargetFrameworkOverride=True.
          Does not fire when the csproj switches shape. -->
-    <Warning Code="MSKIT_SHARED009"
+    <Warning Code="MSKITSHARED009" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskitshared009"
              Condition="'$(MSKit_SkipAudit_TargetFrameworkOverride)'!='True'
                         AND '$(MSKit_TargetFrameworks_Proj)'!=''
                         AND '$(MSKit_TargetFrameworks_Shared)'!=''
@@ -73,12 +73,12 @@
              File="$(MSBuildProjectFullPath)"
              Text="csproj '$(MSBuildProjectName)' declares &lt;TargetFrameworks&gt;$(MSKit_TargetFrameworks_Proj)&lt;/TargetFrameworks&gt; but Directory.Build.props centralizes &lt;TargetFrameworks&gt;$(MSKit_TargetFrameworks_Shared)&lt;/TargetFrameworks&gt; as the default.%0ARecommended: remove the csproj-level &lt;TargetFrameworks&gt; declaration (DBP is the single source of truth).%0ATo override intentionally, add to the csproj &lt;PropertyGroup&gt;:%0A  &lt;MSKit_SkipAudit_TargetFrameworkOverride&gt;True&lt;/MSKit_SkipAudit_TargetFrameworkOverride&gt;" />
 
-    <!-- MSKIT_SHARED010: csproj declares BOTH <TargetFramework> AND <TargetFrameworks>.
+    <!-- MSKITSHARED010: csproj declares BOTH <TargetFramework> AND <TargetFrameworks>.
          Error, non-bypassable. SDK silently ignores <TargetFramework>
          when <TargetFrameworks> is non-empty (cross-targeting wins); the redundant declaration
          is a code smell that should be fixed at source. Uses NODE-presence count (not value)
          so even the legacy <TargetFramework></TargetFramework> "clear" trick fires the audit. -->
-    <Error Code="MSKIT_SHARED010"
+    <Error Code="MSKITSHARED010" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskitshared010"
            Condition="$(_MSKit_TF_ProjNodeCount) &gt; 0 AND $(_MSKit_TFs_ProjNodeCount) &gt; 0"
            File="$(MSBuildProjectFullPath)"
            Text="csproj '$(MSBuildProjectName)' declares BOTH &lt;TargetFramework&gt; AND &lt;TargetFrameworks&gt; in the same project. SDK silently ignores &lt;TargetFramework&gt; when &lt;TargetFrameworks&gt; is non-empty.%0AFix: remove one of these from the csproj &lt;PropertyGroup&gt; - pick the shape you actually want:%0A  &lt;TargetFramework&gt;$(MSKit_TargetFramework_Proj)&lt;/TargetFramework&gt;%0A    -- OR --%0A  &lt;TargetFrameworks&gt;$(MSKit_TargetFrameworks_Proj)&lt;/TargetFrameworks&gt;%0AThis check is not bypassable; declaring both is always wrong." />
@@ -87,7 +87,7 @@
     <PropertyGroup>
       <MSKit_SkipAudit_TreatWarningsAsErrors Condition="'$(MSKit_IsDevEnv)'!='True'">True</MSKit_SkipAudit_TreatWarningsAsErrors>
     </PropertyGroup>
-    <Error Code="MSKIT_SHARED020"
+    <Error Code="MSKITSHARED020" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskitshared020"
            Condition="'$(MSKit_SkipAudit_TreatWarningsAsErrors)'!='True'
                       AND '$(MSKit_TreatWarningsAsErrors_Shared)'!=''
                       AND '$(TreatWarningsAsErrors)'!='$(MSKit_TreatWarningsAsErrors_Shared)'"
diff --git a/manager/.toolkit/msbuild/DragoAnt.MSBuildKit/audit/audit.version.targets b/manager/.toolkit/msbuild/DragoAnt.MSBuildKit/audit/audit.version.targets
index aaea8ee..125aea7 100644
--- a/manager/.toolkit/msbuild/DragoAnt.MSBuildKit/audit/audit.version.targets
+++ b/manager/.toolkit/msbuild/DragoAnt.MSBuildKit/audit/audit.version.targets
@@ -1,8 +1,8 @@
 <Project InitialTargets="RestrictManualVersion;ValidateVersionTemplate;ValidateReleaseTag">
 
-  <!-- Checks for the version engine (version.props / version.targets). Codes MSKIT_VER001..007. -->
+  <!-- Checks for the version engine (version.props / version.targets). Codes MSKITVER001..007. -->
 
-  <!-- MSKIT_VER001: <Version> declared in the csproj while a template strategy is active. -->
+  <!-- MSKITVER001: <Version> declared in the csproj while a template strategy is active. -->
   <Target Name="RestrictManualVersion"
           Condition="'$(MSKit_VersionStrategy)'!='Manual'"
           BeforeTargets="Restore;Build;CoreCompile">
@@ -17,13 +17,13 @@
       <Output TaskParameter="Result" ItemName="_MSKit_VersionCheckNode" />
     </XmlPeek>
 
-    <Error Code="MSKIT_VER001"
+    <Error Code="MSKITVER001" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskitver001"
            Condition="@(_MSKit_VersionCheckNode->Count()) &gt; 0"
            Text="&lt;Version&gt; is declared in the project but MSKit_VersionStrategy='$(MSKit_VersionStrategy)' renders the version from a template, so the declared value is ignored.%0AFix: remove &lt;Version&gt; from the csproj (declare the next version as &lt;VersionPrefix&gt; in Directory.Version.props), or switch to manual versioning in Directory.Build.props:%0A  &lt;MSKit_VersionStrategy&gt;Manual&lt;/MSKit_VersionStrategy&gt;"
            File="$(MSBuildProjectFullPath)" />
   </Target>
 
-  <!-- MSKIT_VER002 / MSKIT_VER003: a template uses a placeholder the engine does not know. -->
+  <!-- MSKITVER002: a template uses a placeholder the engine does not know (MSKITVER003 is reserved, never reported). -->
   <Target Name="ValidateVersionTemplate"
           Condition="'$(MSKit_VersionStrategy)'!='Manual'">
 
@@ -56,35 +56,35 @@ Valid placeholders:
       <_MSKit_UnknownPlaceholder Include="@(_MSKit_TplNameItem)" Exclude="@(_MSKit_ValidPlaceholder)" />
     </ItemGroup>
 
-    <Error Code="MSKIT_VER002"
+    <Error Code="MSKITVER002" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskitver002"
            Condition="@(_MSKit_UnknownPlaceholder->Count()) &gt; 0"
            Text="A version template contains unknown placeholder(s): @(_MSKit_UnknownPlaceholder -> '{%(Identity)}', ', ').%0ATemplates: MSKit_VersionTemplate='$(MSKit_VersionTemplate)', MSKit_StableVersionTemplate='$(MSKit_StableVersionTemplate)', MSKit_ReleaseVersionTemplate='$(MSKit_ReleaseVersionTemplate)', MSKit_PullRequestVersionTemplate='$(MSKit_PullRequestVersionTemplate)'.%0A$(_MSKit_PlaceholderHelp)"
            File="$(MSBuildProjectFullPath)" />
   </Target>
 
-  <!-- MSKIT_VER004: the VersionTag strategy rendered an empty version. -->
+  <!-- MSKITVER004: the VersionTag strategy rendered an empty version. -->
   <Target Name="ValidateRenderedVersionForVersionTag"
           AfterTargets="RenderVersionFromTemplate"
           Condition="'$(MSKit_VersionStrategy)'=='VersionTag'">
-    <Error Code="MSKIT_VER004"
+    <Error Code="MSKITVER004" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskitver004"
            Condition="'$(Version)'==''"
            Text="MSKit_VersionStrategy='VersionTag' but VersionTag is empty.%0AFix: pass it on the command line (-p:VersionTag=1.2.3) or use MSKit_VersionStrategy=ReleaseTag, which reads the version from the release tag."
            File="$(MSBuildProjectFullPath)" />
   </Target>
 
-  <!-- MSKIT_VER006: a release tag that is not SemVer 2.0. MSKIT_VER007: its version core differs
+  <!-- MSKITVER006: a release tag that is not SemVer 2.0. MSKITVER007: its version core differs
        from the VersionPrefix the repository declares. -->
   <Target Name="ValidateReleaseTag"
           Condition="'$(MSKit_IsReleaseTag)'=='True' AND '$(MSKit_ExplicitVersion)'=='' AND '$(MSKit_VersionStrategy)'!='Manual' AND '$(MSKit_VersionStrategy)'!='DevEnv'"
           BeforeTargets="Restore;Build">
-    <Error Code="MSKIT_VER006"
+    <Error Code="MSKITVER006" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskitver006"
            Condition="'$(MSKit_IsReleaseTagValid)'!='true'"
            Text="Release tag '$(MSKit_ReleaseTagRaw)' is not a valid version. After removing a leading 'v' it must be SemVer 2.0: MAJOR.MINOR.PATCH with an optional -prerelease and +metadata (for example v2.1.0 or 2.1.0-beta.1).%0AFix: delete the tag and the GitHub release, then create a release whose tag is a version."
            File="$(MSBuildProjectFullPath)" />
     <PropertyGroup Condition="'$(MSKit_IsReleaseTagValid)'=='true'">
       <_MSKit_ReleaseTagCore>$([System.Text.RegularExpressions.Regex]::Match('$(MSKit_ReleaseTag)', '^\d+\.\d+\.\d+').Value)</_MSKit_ReleaseTagCore>
     </PropertyGroup>
-    <Warning Code="MSKIT_VER007"
+    <Warning Code="MSKITVER007" HelpLink="$(MSKit_CodesHelpBaseUrl)#mskitver007"
              Condition="'$(MSKit_SkipAudit_ReleaseTagPrefix)'!='True' AND '$(_MSKit_ReleaseTagCore)'!='' AND '$(MSKit_DeclaredVersionPrefix)'!='' AND '$(MSKit_DeclaredVersionPrefix)'!='$(_MSKit_ReleaseTagCore)'"
              Text="Release tag '$(MSKit_ReleaseTagRaw)' has version core $(_MSKit_ReleaseTagCore), but the repository declares VersionPrefix $(MSKit_DeclaredVersionPrefix).%0AFix: bump &lt;VersionPrefix&gt; in Directory.Version.props after the release so branch and pull-request builds sort above it. Set MSKit_SkipAudit_ReleaseTagPrefix=True to silence this."
              File="$(MSBuildProjectFullPath)" />
diff --git a/manager/.toolkit/msbuild/DragoAnt.MSBuildKit/twae.shared.init.props b/manager/.toolkit/msbuild/DragoAnt.MSBuildKit/twae.shared.init.props
index ffddb18..072f863 100644
--- a/manager/.toolkit/msbuild/DragoAnt.MSBuildKit/twae.shared.init.props
+++ b/manager/.toolkit/msbuild/DragoAnt.MSBuildKit/twae.shared.init.props
@@ -1,6 +1,6 @@
 <Project>
 
-  <!-- Captured before the csproj body so MSKIT_SHARED020 can compare against the shared value. -->
+  <!-- Captured before the csproj body so MSKITSHARED020 can compare against the shared value. -->
   <PropertyGroup>
     <MSKit_TreatWarningsAsErrors_Shared>$(TreatWarningsAsErrors)</MSKit_TreatWarningsAsErrors_Shared>
   </PropertyGroup>
diff --git a/manager/.toolkit/msbuild/DragoAnt.MSBuildKit/version.props b/manager/.toolkit/msbuild/DragoAnt.MSBuildKit/version.props
index 6e356cf..83c5779 100644
--- a/manager/.toolkit/msbuild/DragoAnt.MSBuildKit/version.props
+++ b/manager/.toolkit/msbuild/DragoAnt.MSBuildKit/version.props
@@ -97,7 +97,7 @@
     <_MSKit_Ph_versionTag>$(VersionTag)</_MSKit_Ph_versionTag>
     <_MSKit_Ph_releaseTag Condition="'$(MSKit_IsReleaseTagValid)'=='true'">$(MSKit_ReleaseTag)</_MSKit_Ph_releaseTag>
     <!-- An invalid tag renders a valid placeholder so restore does not fail first with an opaque
-         error; ValidateReleaseTag then stops the build with MSKIT_VER006. -->
+         error; ValidateReleaseTag then stops the build with MSKITVER006. -->
     <_MSKit_Ph_releaseTag Condition="'$(MSKit_IsReleaseTagValid)'!='true'">0.0.0-invalid-release-tag</_MSKit_Ph_releaseTag>
     <_MSKit_Ph_prNumber>$(MSKit_PullRequestNumber)</_MSKit_Ph_prNumber>
     <_MSKit_Ph_buildNumber>$(MSKit_BuildNumber)</_MSKit_Ph_buildNumber>
diff --git a/tests/codes.sh b/tests/codes.sh
new file mode 100644
index 0000000..3f6c937
--- /dev/null
+++ b/tests/codes.sh
@@ -0,0 +1,23 @@
+# Codes: every code is spelled MSKIT<FAMILY><nnn>, and every diagnostic links to its section of
+# docs/reference/codes.md through MSKit_CodesHelpBaseUrl. The terminal logger prints the HelpLink as
+# an OSC 8 hyperlink on the code, which is how the link is read back here.
+# Sourced by tests/run.sh: uses its pass, bad, $out, $here, $lib, $fixtures, $clean_env and $ci_env.
+
+if grep -rn 'MSKIT[_]' "$here/kit" > "$out/codes-old-spelling.log"; then
+  bad "codes: the kit spells a code with an underscore (see $out/codes-old-spelling.log)"; head -n 5 "$out/codes-old-spelling.log"
+else
+  pass "codes: no code in the kit is spelled with an underscore"
+fi
+
+codes_url="https://github.com/DragoAnt/MSBuildKit/blob/main/docs/reference/codes.md"
+$clean_env $ci_env GITHUB_EVENT_NAME=release GITHUB_REF_TYPE=tag GITHUB_REF_NAME=release-x GITHUB_REF=refs/tags/release-x \
+  dotnet restore "$lib" -nologo -tl:on > "$out/codes-helplink-ver006.log" 2>&1 || true
+grep -qF "]8;;$codes_url#mskitver006" "$out/codes-helplink-ver006.log" \
+  && pass "codes: MSKITVER006 links to $codes_url#mskitver006" || bad "codes: MSKITVER006 has no HelpLink to its section (see $out/codes-helplink-ver006.log)"
+
+$clean_env dotnet pack "$fixtures/BadPackage/BadPackage.csproj" -c Release -nologo -tl:on -o "$out/codes-helplink-pkg" \
+  -p:MSKit_PackageChecksAsErrors=False -p:MSKit_CodesHelpBaseUrl=https://codes.example/kit.md > "$out/codes-helplink-pkg.log" 2>&1 || true
+for code in mskitpkg001 mskitpkg010; do
+  grep -qF "]8;;https://codes.example/kit.md#$code" "$out/codes-helplink-pkg.log" \
+    && pass "codes: MSKit_CodesHelpBaseUrl moves the $code link" || bad "codes: the $code link ignores MSKit_CodesHelpBaseUrl (see $out/codes-helplink-pkg.log)"
+done
diff --git a/tests/docs.sh b/tests/docs.sh
index 50c82c0..2aad5d2 100644
--- a/tests/docs.sh
+++ b/tests/docs.sh
@@ -5,7 +5,8 @@ dc_log="$out/docs-check.log"
 if sh "$here/tools/docs-check.sh" > "$dc_log" 2>&1; then pass "docs: $(tail -n 1 "$dc_log" | sed 's/^docs-check: //')"
 else bad "docs: tools/docs-check.sh found problems (see $dc_log)"; cat "$dc_log"; fi
 
-# A copy with one property row, one code section, one name, one link and one anchor broken must fail on each.
+# A copy with one property row, one code section, one name, one link, one anchor, two HelpLinks and
+# the old code spelling in four places broken must fail on each.
 dc_copy() {
   rm -rf "$1"; mkdir -p "$1/kit/.toolkit" "$1/samples/MinimalLibrary"
   cp -R "$here/kit/.toolkit/msbuild" "$1/kit/.toolkit/msbuild"
@@ -13,22 +14,22 @@ dc_copy() {
   for f in README.md CONTRIBUTING.md SECURITY.md CHANGELOG.md LICENSE; do cp "$here/$f" "$1/$f"; done
   mkdir -p "$1/tools"; cp "$here/tools/docs-check.sh" "$1/tools/docs-check.sh"
 }
+u=_
 dc_bad="$out/docs-check-broken"
 dc_copy "$dc_bad"
+dc_kit="$dc_bad/kit/.toolkit/msbuild/DragoAnt.MSBuildKit/audit"
 grep -v '^| `MSKit_SemVerRegex` |' "$here/docs/reference/properties.md" > "$dc_bad/docs/reference/properties.md"
-sed 's/^### MSKITVER004$/### Gone/; s/^### MSKITPAP002$/### MSKIT_PAP002/' "$here/docs/reference/codes.md" > "$dc_bad/docs/reference/codes.md"
-printf '\nSee `MSKit_NoSuchProperty`, `MSKIT_VER099`, [gone](./no-such-page.md), [anchor](./build.md#no-such-heading) and [bare](build.md).\n' >> "$dc_bad/docs/troubleshooting.md"
+sed "s/^### MSKITVER004\$/### Gone/; s/^### MSKITPAP002\$/### MSKIT${u}PAP002/" "$here/docs/reference/codes.md" > "$dc_bad/docs/reference/codes.md"
+printf '\nSee `MSKit_NoSuchProperty`, `MSKITVER099`, formerly `MSKIT%sVER006`, [gone](./no-such-page.md), [anchor](./build.md#no-such-heading) and [bare](build.md).\n' "$u" >> "$dc_bad/docs/troubleshooting.md"
+sed "s/^## \[Unreleased\]\$/&\n\n- The MSKIT${u}PKG checks./" "$here/CHANGELOG.md" > "$dc_bad/CHANGELOG.md"
+sed 's/ HelpLink="$(MSKit_CodesHelpBaseUrl)#mskitver006"//; s/#mskitver007"/#mskitver001"/' "$here/kit/.toolkit/msbuild/DragoAnt.MSBuildKit/audit/audit.version.targets" > "$dc_kit/audit.version.targets"
+sed "s/Code=\"MSKITRES002\"/Code=\"MSKIT${u}RES002\"/" "$here/kit/.toolkit/msbuild/DragoAnt.MSBuildKit/audit/audit.restrict.packages.targets" > "$dc_kit/audit.restrict.packages.targets"
 sh "$dc_bad/tools/docs-check.sh" > "$out/docs-check-broken.log" 2>&1 && bad "docs: the check passed a broken copy (see $out/docs-check-broken.log)"
 for needle in "property MSKit_SemVerRegex" "code MSKITVER004" "write the heading as MSKITPAP002" "mentions MSKit_NoSuchProperty" \
-    "mentions MSKITVER099" "no-such-page.md points at a missing file" "no-such-heading names a heading" "build.md must start with ./"; do
-  grep -qF "$needle" "$out/docs-check-broken.log" && pass "docs: the check reports '$needle'" || bad "docs: the check missed '$needle' (see $out/docs-check-broken.log)"
+    "mentions MSKITVER099" "no-such-page.md points at a missing file" "no-such-heading names a heading" "build.md must start with ./" \
+    "MSKITVER006 has no HelpLink" "MSKITVER007 has HelpLink=" "HelpLink anchor #mskitver004 has no heading" \
+    "docs/troubleshooting.md:|old spelling of MSKITVER006" "CHANGELOG.md:|old spelling of MSKITPKG" \
+    "audit.restrict.packages.targets:|old spelling of MSKITRES002" "docs/reference/codes.md:|old spelling of MSKITPAP002"; do
+  where=${needle%%|*}; what=${needle#*|}
+  grep -F "$where" "$out/docs-check-broken.log" | grep -qF "$what" && pass "docs: the check reports '$needle'" || bad "docs: the check missed '$needle' (see $out/docs-check-broken.log)"
 done
-
-# The planned code rename (MSKIT_VER006 -> MSKITVER006) must not break the check.
-dc_renamed="$out/docs-check-renamed"
-dc_copy "$dc_renamed"
-sed 's/MSKIT_VER006/MSKITVER006/g' "$here/kit/.toolkit/msbuild/DragoAnt.MSBuildKit/audit/audit.version.targets" \
-  > "$dc_renamed/kit/.toolkit/msbuild/DragoAnt.MSBuildKit/audit/audit.version.targets"
-grep -q 'Code="MSKITVER006"' "$dc_renamed/kit/.toolkit/msbuild/DragoAnt.MSBuildKit/audit/audit.version.targets" || bad "docs: the rename fixture did not rename MSKIT_VER006"
-sh "$dc_renamed/tools/docs-check.sh" > "$out/docs-check-renamed.log" 2>&1 \
-  && pass "docs: a code spelled without the underscore still matches its section" || { bad "docs: the renamed code broke the check (see $out/docs-check-renamed.log)"; cat "$out/docs-check-renamed.log"; }
diff --git a/tests/fixtures/PackageChecks/BadPackage/BadPackage.csproj b/tests/fixtures/PackageChecks/BadPackage/BadPackage.csproj
index 1bac119..9c2b721 100644
--- a/tests/fixtures/PackageChecks/BadPackage/BadPackage.csproj
+++ b/tests/fixtures/PackageChecks/BadPackage/BadPackage.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
-  <!-- Breaks one package rule on purpose per check: tests/run.sh expects every listed MSKIT_PKG code. -->
+  <!-- Breaks one package rule on purpose per check: tests/run.sh expects every listed MSKITPKG code. -->
   <PropertyGroup>
     <PackageIconPath>missing.png</PackageIconPath>
     <PackageIconUrl>https://example.com/icon.png</PackageIconUrl>
diff --git a/tests/package-icon.sh b/tests/package-icon.sh
index 0a42146..6e18a21 100644
--- a/tests/package-icon.sh
+++ b/tests/package-icon.sh
@@ -30,7 +30,7 @@ ic_quiet() { grep -q "$2" "$out/icon-$1.log" && bad "icon $1 reports $2 (see $ou
 ic_pack default Icons
 ic_icon default icon.png
 ic_entry default icon.png
-ic_quiet default MSKIT_PKG015
+ic_quiet default MSKITPKG015
 
 # A JPEG PackageIconPath keeps its extension.
 ic_pack jpg Icons -p:FixtureIcon=icon.jpg
@@ -38,12 +38,12 @@ ic_icon jpg icon.jpg
 ic_entry jpg icon.jpg
 ic_no_entry jpg icon.png
 ic_quiet jpg NU5046
-ic_quiet jpg MSKIT_PKG015
+ic_quiet jpg MSKITPKG015
 
 # A JPEG of the wrong size is still reported.
 ic_pack jpg-small Icons -p:FixtureIcon=small.jpg
 ic_icon jpg-small icon.jpg
-ic_warns jpg-small MSKIT_PKG015
+ic_warns jpg-small MSKITPKG015
 
 # An upper-case extension is lowercased.
 ic_pack upper Icons -p:FixtureIcon=ICON.PNG
@@ -57,4 +57,4 @@ ic_pack own Own
 ic_icon own logo.png
 ic_entry own logo.png
 ic_no_entry own icon.png
-ic_quiet own MSKIT_PKG015
+ic_quiet own MSKITPKG015
diff --git a/tests/package-readme.sh b/tests/package-readme.sh
index 866943c..99eb5f3 100644
--- a/tests/package-readme.sh
+++ b/tests/package-readme.sh
@@ -60,7 +60,7 @@ rf_has github "[fenced](./fenced.md)"
 rf_has github "<!-- nuget:skip -->"
 awk '/^## /{exit} /\[Release notes\]/{found=1} END{exit !found}' "$out/readme-github.md" \
   && pass "readme github: the release-notes link is in the overview" || bad "readme github: the release-notes link is not in the overview"
-for code in MSKIT_PKG009 MSKIT_PKG012 MSKIT_PKG016 MSKIT_PKG017 MSKIT_PKG020 MSKIT_PKG021 MSKIT_PKG022; do rf_quiet github $code; done
+for code in MSKITPKG009 MSKITPKG012 MSKITPKG016 MSKITPKG017 MSKITPKG020 MSKITPKG021 MSKITPKG022; do rf_quiet github $code; done
 rf_notes github "https://github.com/DragoAnt/Fixture/releases"
 
 # Incremental: the same inputs leave the generated file alone; a new commit regenerates it.
@@ -97,17 +97,17 @@ rf_has gitlab "[the docs folder](https://gitlab.com/dragoant/sub/fixture/-/tree/
 rf_has gitlab "![diagram](https://gitlab.com/dragoant/sub/fixture/-/raw/$sha/$rel/docs/diagram.png)"
 rf_has gitlab "[Release notes](https://gitlab.com/dragoant/sub/fixture/-/releases)"
 rf_has gitlab "[Issues](https://gitlab.com/dragoant/sub/fixture/-/issues)"
-rf_quiet gitlab MSKIT_PKG021
-rf_quiet gitlab MSKIT_PKG017
-rf_quiet gitlab MSKIT_PKG016
+rf_quiet gitlab MSKITPKG021
+rf_quiet gitlab MSKITPKG017
+rf_quiet gitlab MSKITPKG016
 rf_notes gitlab "https://gitlab.com/dragoant/sub/fixture/-/releases"
 rf_pack gitlab-again Observer $gl
-rf_quiet gitlab-again MSKIT_PKG016
+rf_quiet gitlab-again MSKITPKG016
 rf_notes gitlab-again "https://gitlab.com/dragoant/sub/fixture/-/releases"
 rf_pack gitlab-no-releases Observer $gl -p:MSKit_ReleasesUrl=
-rf_warns gitlab-no-releases MSKIT_PKG016
+rf_warns gitlab-no-releases MSKITPKG016
 rf_pack gitlab-no-default Observer $gl -p:MSKit_DefaultReleaseNotes=False
-rf_warns gitlab-no-default MSKIT_PKG016
+rf_warns gitlab-no-default MSKITPKG016
 rf_pack gitlab-notes Observer $gl "-p:PackageReleaseNotes=See the changelog."
 rf_notes gitlab-notes "See the changelog."
 
@@ -116,29 +116,29 @@ rf_pack gitlab-self Observer -p:RepositoryUrl=https://git.example.org/team/fixtu
 rf_has gitlab-self "[the guide](https://git.example.org/team/fixture/-/blob/$sha/$rel/docs/guide.md)"
 rf_has gitlab-self "![diagram](https://git.example.org/team/fixture/-/raw/$sha/$rel/docs/diagram.png)"
 rf_has gitlab-self "[Issues](https://git.example.org/team/fixture/-/issues)"
-rf_quiet gitlab-self MSKIT_PKG016
+rf_quiet gitlab-self MSKITPKG016
 rf_notes gitlab-self "https://git.example.org/team/fixture/-/releases"
-rf_warns gitlab-self MSKIT_PKG021
-grep "warning MSKIT_PKG021" "$out/readme-gitlab-self.log" | grep -q "line 11" \
-  && pass "readme gitlab-self: MSKIT_PKG021 names the README line" || bad "readme gitlab-self: MSKIT_PKG021 does not name line 11"
-grep "warning MSKIT_PKG021" "$out/readme-gitlab-self.log" | grep -q "img.shields.io" \
+rf_warns gitlab-self MSKITPKG021
+grep "warning MSKITPKG021" "$out/readme-gitlab-self.log" | grep -q "line 11" \
+  && pass "readme gitlab-self: MSKITPKG021 names the README line" || bad "readme gitlab-self: MSKITPKG021 does not name line 11"
+grep "warning MSKITPKG021" "$out/readme-gitlab-self.log" | grep -q "img.shields.io" \
   && bad "readme gitlab-self: an allowed image host was warned" || pass "readme gitlab-self: allowed image hosts are not warned"
 
 # An unknown host: links stay relative, and the render checks on the generated file catch them.
 rf_pack unknown Observer -p:RepositoryUrl=https://code.example.net/team/fixture -p:RepositoryCommit=$sha
-rf_warns unknown MSKIT_PKG020
-rf_warns unknown MSKIT_PKG017
-rf_warns unknown MSKIT_PKG016
+rf_warns unknown MSKITPKG020
+rf_warns unknown MSKITPKG017
+rf_warns unknown MSKITPKG016
 rf_has unknown "[the guide](./docs/guide.md)"
 rf_pack unknown-releases Observer -p:RepositoryUrl=https://code.example.net/team/fixture -p:RepositoryCommit=$sha \
   "-p:MSKit_ReleasesUrl=https://code.example.net/team/fixture/changes"
-rf_quiet unknown-releases MSKIT_PKG016
+rf_quiet unknown-releases MSKITPKG016
 rf_notes unknown-releases "https://code.example.net/team/fixture/changes"
 
 # Overrides: provider, templates, an empty releases URL (link omitted), a custom issues URL.
 rf_pack provider Observer -p:RepositoryUrl=https://code.example.net/team/fixture -p:RepositoryCommit=$sha -p:MSKit_RepoProvider=GitLab
 rf_has provider "[the guide](https://code.example.net/team/fixture/-/blob/$sha/$rel/docs/guide.md)"
-rf_quiet provider MSKIT_PKG020
+rf_quiet provider MSKITPKG020
 rf_pack override Observer $gh \
   "-p:MSKit_RepoBlobUrlTemplate=https://src.example.net/{repoPath}/view/{commit}/{path}" \
   "-p:MSKit_RepoRawUrlTemplate=https://raw.githubusercontent.com/mirror/{repo}/{commit}/{path}" \
@@ -150,7 +150,7 @@ rf_has override "[Issues](https://tracker.example.net/fixture)"
 
 # A private repository: the links will not open for package readers.
 rf_pack private Observer $gh -p:MSKit_RepositoryVisibility=private
-rf_warns private MSKIT_PKG022
+rf_warns private MSKITPKG022
 
 # Title (MSKit_PackageReadmeTitle): the first level-1 heading becomes the package id, per package.
 rf_first() {
diff --git a/tests/run.sh b/tests/run.sh
index cf521c9..e57fac4 100644
--- a/tests/run.sh
+++ b/tests/run.sh
@@ -49,11 +49,11 @@ explicit=$($clean_env $ci_env GITHUB_EVENT_NAME=release GITHUB_REF_TYPE=tag GITH
 
 if $clean_env $ci_env GITHUB_EVENT_NAME=release GITHUB_REF_TYPE=tag GITHUB_REF_NAME=release-x GITHUB_REF=refs/tags/release-x \
     dotnet restore "$lib" -nologo > "$out/invalid-tag.log" 2>&1; then
-  bad "tag release-x: restore succeeded, expected MSKIT_VER006"
-elif grep -q "MSKIT_VER006" "$out/invalid-tag.log"; then
-  pass "tag release-x -> restore fails with MSKIT_VER006"
+  bad "tag release-x: restore succeeded, expected MSKITVER006"
+elif grep -q "MSKITVER006" "$out/invalid-tag.log"; then
+  pass "tag release-x -> restore fails with MSKITVER006"
 else
-  bad "tag release-x: restore failed without MSKIT_VER006 (see $out/invalid-tag.log)"
+  bad "tag release-x: restore failed without MSKITVER006 (see $out/invalid-tag.log)"
 fi
 
 $clean_env dotnet build "$sample/MinimalLibrary.slnx" -c Release -nologo > "$out/build.log" 2>&1 && pass "sample builds" || { bad "sample build (see $out/build.log)"; tail -n 30 "$out/build.log"; }
@@ -93,7 +93,7 @@ fi
 
 $clean_env dotnet pack "$fixtures/PackageChecks.slnx" -c Release -nologo -o "$out/fixtures" -p:MSKit_PackageChecksAsErrors=False > "$out/checks.log" 2>&1 || true
 for code in 001 002 003 004 005 006 007 008 009 010 011 012 013 014 015 016 017 018 019; do
-  grep -q "warning MSKIT_PKG$code" "$out/checks.log" && pass "check MSKIT_PKG$code fires" || bad "check MSKIT_PKG$code did not fire (see $out/checks.log)"
+  grep -q "warning MSKITPKG$code" "$out/checks.log" && pass "check MSKITPKG$code fires" || bad "check MSKITPKG$code did not fire (see $out/checks.log)"
 done
 grep -q "<div>" "$out/checks.log" && bad "HTML inside a code fence was reported" || pass "HTML inside a code fence is ignored"
 
@@ -101,16 +101,17 @@ if $clean_env $ci_env GITHUB_EVENT_NAME=push GITHUB_REF_TYPE=branch GITHUB_REF_N
     dotnet pack "$fixtures/BadPackage/BadPackage.csproj" -c Release -nologo -o "$out/fixtures-ci" > "$out/checks-ci.log" 2>&1; then
   bad "the checks did not fail the CI pack"
 else
-  grep -q "error MSKIT_PKG001" "$out/checks-ci.log" && pass "checks are errors on CI" || bad "CI pack failed without MSKIT_PKG errors (see $out/checks-ci.log)"
+  grep -q "error MSKITPKG001" "$out/checks-ci.log" && pass "checks are errors on CI" || bad "CI pack failed without MSKITPKG errors (see $out/checks-ci.log)"
 fi
 
 $clean_env dotnet pack "$fixtures/BadPackage/BadPackage.csproj" -c Release -nologo -o "$out/fixtures-skip" \
   "-p:MSKit_SkipPackageChecks=All" > "$out/checks-skip.log" 2>&1 || true
-grep -q "MSKIT_PKG" "$out/checks-skip.log" && bad "MSKit_SkipPackageChecks=All did not silence the checks" || pass "MSKit_SkipPackageChecks=All silences the checks"
+grep -q "MSKITPKG" "$out/checks-skip.log" && bad "MSKit_SkipPackageChecks=All did not silence the checks" || pass "MSKit_SkipPackageChecks=All silences the checks"
 
 . "$here/tests/package-readme.sh"
 . "$here/tests/tfm-constants.sh"
 . "$here/tests/package-icon.sh"
+. "$here/tests/codes.sh"
 . "$here/tests/docs.sh"
 
 echo
diff --git a/tests/tfm-constants.sh b/tests/tfm-constants.sh
index e65e60e..a35c671 100644
--- a/tests/tfm-constants.sh
+++ b/tests/tfm-constants.sh
@@ -11,11 +11,11 @@ tfm_expect() {
 tfm_validate() {
   name="$1"; expect="$2"; shift 2
   if $clean_env dotnet msbuild "$tfm_fixture/$name/$name.csproj" -nologo -t:ValidateXUnitV3TFM "$@" > "$out/tfm-$name.log" 2>&1; then
-    [ "$expect" = ok ] && pass "tfm $name passes MSKIT_TEST005" || bad "tfm $name: expected MSKIT_TEST005, the check passed"
-  elif grep -q "MSKIT_TEST005" "$out/tfm-$name.log"; then
-    [ "$expect" = fail ] && pass "tfm $name fails with MSKIT_TEST005" || bad "tfm $name: false MSKIT_TEST005 (see $out/tfm-$name.log)"
+    [ "$expect" = ok ] && pass "tfm $name passes MSKITTEST005" || bad "tfm $name: expected MSKITTEST005, the check passed"
+  elif grep -q "MSKITTEST005" "$out/tfm-$name.log"; then
+    [ "$expect" = fail ] && pass "tfm $name fails with MSKITTEST005" || bad "tfm $name: false MSKITTEST005 (see $out/tfm-$name.log)"
   else
-    bad "tfm $name: the check failed without MSKIT_TEST005 (see $out/tfm-$name.log)"
+    bad "tfm $name: the check failed without MSKITTEST005 (see $out/tfm-$name.log)"
   fi
 }
 
diff --git a/tools/docs-check.sh b/tools/docs-check.sh
index f7bd11b..77b584e 100644
--- a/tools/docs-check.sh
+++ b/tools/docs-check.sh
@@ -1,9 +1,9 @@
 #!/bin/sh
 # Keeps the documentation honest against the kit: every property and item the kit defines has a row
-# in docs/reference/properties.md, every code it reports a section headed by the code id without the
-# underscore in docs/reference/codes.md, every MSKit_ name and MSKIT_ code the docs mention exists in
-# the kit, and every relative link resolves (anchors included).
-# Usage: sh tools/docs-check.sh [--root DIR] [--list properties|items|codes]
+# in docs/reference/properties.md, every code it reports a section headed by the code id in
+# docs/reference/codes.md, every <Warning>/<Error> a HelpLink to that section, every MSKit_ name and
+# code the docs mention exists in the kit, no file spells a code the old way, and every link resolves.
+# Usage: sh tools/docs-check.sh [--root DIR] [--list properties|items|codes|diagnostics]
 set -eu
 
 root=$(cd "$(dirname "$0")/.." && pwd)
@@ -16,7 +16,7 @@ while [ $# -gt 0 ]; do
     *) echo "docs-check: unknown argument '$1'" >&2; exit 2 ;;
   esac
 done
-case "$list" in ""|properties|items|codes) ;; *) echo "docs-check: --list takes properties, items or codes" >&2; exit 2 ;; esac
+case "$list" in ""|properties|items|codes|diagnostics) ;; *) echo "docs-check: --list takes properties, items, codes or diagnostics" >&2; exit 2 ;; esac
 
 [ -d "$root/kit/.toolkit/msbuild" ] || { echo "docs-check: no kit at $root/kit/.toolkit/msbuild" >&2; exit 2; }
 work=$(mktemp -d)
@@ -24,14 +24,14 @@ trap 'rm -rf "$work"' EXIT INT TERM
 cd "$root"
 
 # Kit inventory with XML comments removed, one process for every file:
-# "P <name> <where>" property set, "I" item, "R" property read, "C" diagnostic code.
-# A code is keyed by its id without the underscore (MSKIT_VER006 and MSKITVER006 are one code).
+# "P <name> <where>" property set, "I" item, "R" property read, "C" diagnostic code,
+# "W <where> <Code> <HelpLink>" a <Warning> or <Error> task ("-" for a missing attribute).
 find kit/.toolkit/msbuild -type f \( -name '*.props' -o -name '*.targets' -o -name '*.cs.txt' \) -exec awk '
-  FNR == 1 { incomment = 0; pg = 0; ig = 0 }
+  FNR == 1 { incomment = 0; pg = 0; ig = 0; inel = 0 }
   { sub(/\r$/, "") }
   FILENAME ~ /\.cs\.txt$/ {
     rest = $0
-    while (match(rest, /"MSKIT_?[A-Z]+[0-9][0-9][0-9]"/)) { print "C", id(substr(rest, RSTART + 1, RLENGTH - 2)), FILENAME ":" FNR; rest = substr(rest, RSTART + RLENGTH) }
+    while (match(rest, /"MSKIT[A-Z]+[0-9][0-9][0-9]"/)) { print "C", substr(rest, RSTART + 1, RLENGTH - 2), FILENAME ":" FNR; rest = substr(rest, RSTART + RLENGTH) }
     next
   }
   {
@@ -53,9 +53,17 @@ find kit/.toolkit/msbuild -type f \( -name '*.props' -o -name '*.targets' -o -na
     rest = out
     while (match(rest, /\$\(MSKit_[A-Za-z0-9_]+/)) { print "R", substr(rest, RSTART + 2, RLENGTH - 2), FILENAME ":" FNR; rest = substr(rest, RSTART + RLENGTH) }
     rest = out
-    while (match(rest, /MSKIT_?[A-Z]+[0-9][0-9][0-9]/)) { print "C", id(substr(rest, RSTART, RLENGTH)), FILENAME ":" FNR; rest = substr(rest, RSTART + RLENGTH) }
+    while (match(rest, /MSKIT[A-Z]+[0-9][0-9][0-9]/)) { print "C", substr(rest, RSTART, RLENGTH), FILENAME ":" FNR; rest = substr(rest, RSTART + RLENGTH) }
+    if (!inel && (match(out, /<(Warning|Error)[[:space:]\/>]/) || match(out, /<(Warning|Error)$/))) { inel = 1; el = substr(out, RSTART); elat = FILENAME ":" FNR }
+    else if (inel) el = el " " out
+    if (inel && (e = closed(el))) { el = substr(el, 1, e); print "W", elat, attr(el, "Code"), attr(el, "HelpLink"); inel = 0 }
   }
-  function id(c) { sub(/_/, "", c); return c }' {} + > "$work/raw"
+  function closed(s,   i, c, q) { for (i = 1; i <= length(s); i++) { c = substr(s, i, 1); if (c == "\"") q = !q; else if (c == ">" && !q) return i }; return 0 }
+  function attr(s, name,   v) {
+    if (!match(s, "[[:space:]]" name "=\"[^\"]*\"")) return "-"
+    v = substr(s, RSTART, RLENGTH); sub(/^[[:space:]]*[A-Za-z]+="/, "", v); sub(/"$/, "", v)
+    return v == "" ? "-" : v
+  }' {} + > "$work/raw"
 
 # Public names: MSKit_* (set or read) and Is* (set); never the kit's own _-prefixed state.
 # Each is listed with the first place that sets it, else the first place that reads it.
@@ -66,6 +74,7 @@ awk -v dir="$work" '
     la = a; sub(/^.*:/, "", la); lb = b; sub(/^.*:/, "", lb)
     return fa < fb || (fa == fb && la + 0 < lb + 0)
   }
+  $1 == "W" { print $2 "\t" $3 "\t" $4 > (dir "/diagnostics"); next }
   $1 == "C" { if (better($3, c[$2])) c[$2] = $3; next }
   $1 == "I" { if (better($3, i[$2])) i[$2] = $3; next }
   $1 == "P" && ($2 ~ /^MSKit_/ || $2 ~ /^Is[A-Z]/) { if (better($3, set[$2])) set[$2] = $3; next }
@@ -76,10 +85,23 @@ awk -v dir="$work" '
     for (n in set) print n "\t" set[n] "\t" (n in read ? "set, read" : "set") > (dir "/properties")
     for (n in read) if (!(n in set)) print n "\t" read[n] "\tread" > (dir "/properties")
   }' "$work/raw"
-for k in properties items codes; do touch "$work/$k"; sort -o "$work/$k" "$work/$k"; done
+for k in properties items codes diagnostics; do touch "$work/$k"; sort -o "$work/$k" "$work/$k"; done
 
 if [ -n "$list" ]; then cat "$work/$list"; exit 0; fi
 
+# Codes are spelled MSKIT<FAMILY><nnn>. The old spelling, an underscore after the prefix (a code or a
+# family), may appear only as "formerly `...`" in the code reference and in released changelog sections.
+if [ -e .git ]; then git ls-files -co --exclude-standard
+else find . \( -name .git -o -name bin -o -name obj -o -name dist -o -name .claude -o -name node_modules -o -name .toolkit \) -prune \
+  -o -type f -print | sed 's|^\./||'; find kit/.toolkit -type f; fi > "$work/files"
+released=$(grep -n '^## \[[0-9]' CHANGELOG.md 2>/dev/null | head -n 1 | cut -d: -f1)
+tr '\n' '\0' < "$work/files" | xargs -0 grep -nI 'MSKIT[_]' /dev/null 2>/dev/null \
+  | awk -v released="${released:-0}" '
+      { sub(/\r$/, ""); p = index($0, ":"); f = substr($0, 1, p - 1); rest = substr($0, p + 1); p = index(rest, ":"); ln = substr(rest, 1, p - 1); text = substr(rest, p + 1) }
+      f == "CHANGELOG.md" && released > 0 && ln + 0 >= released { next }
+      f == "docs/reference/codes.md" { gsub(/formerly `MSKIT[_][A-Z]+[0-9][0-9][0-9]`/, "", text) }
+      { while (match(text, /MSKIT[_][A-Z]*[0-9]*/)) { print f ":" ln "\t" substr(text, RSTART, RLENGTH); text = substr(text, RSTART + RLENGTH) } }' > "$work/oldspelling" || true
+
 # Every Markdown file a reader sees, and every path in the repository for the link check.
 { for f in README.md CONTRIBUTING.md SECURITY.md; do [ -f "$f" ] && echo "$f"; done
   [ -d docs ] && find docs -type f -name '*.md' | sort; } > "$work/docs.lst"
@@ -98,9 +120,9 @@ awk -v dir="$work" '
     split($0, cell, "|"); c = cell[2]
     while (match(c, /`[^`]+`/)) { print "D\t" f "\t" substr(c, RSTART + 1, RLENGTH - 2); c = substr(c, RSTART + RLENGTH) }
   }
-  f == "docs/reference/codes.md" && /^#+[[:space:]]+`?MSKIT_?[A-Z]+[0-9][0-9][0-9]/ {
-    match($0, /MSKIT_?[A-Z]+[0-9][0-9][0-9]/); c = substr($0, RSTART, RLENGTH)
-    print (c ~ /^MSKIT_/ ? "U\t" f ":" FNR "\t" c : "D\t" f "\t" c)
+  f == "docs/reference/codes.md" && /^#+[[:space:]]+`?MSKIT[_]?[A-Z]+[0-9][0-9][0-9]/ {
+    match($0, /MSKIT[_]?[A-Z]+[0-9][0-9][0-9]/); c = substr($0, RSTART, RLENGTH)
+    print (c ~ /^MSKIT[_]/ ? "U\t" f ":" FNR "\t" c : "D\t" f "\t" c)
   }
   { line = $0; gsub(/`[^`]*`/, "", line)
     while (match(line, /\]\([^) ]+\)/)) { print "L\t" f "\t" FNR "\t" d "\t" substr(line, RSTART + 2, RLENGTH - 3); line = substr(line, RSTART + RLENGTH) } }
@@ -109,7 +131,7 @@ awk -v dir="$work" '
     rest = $0
     while (match(rest, /MSKit_[A-Za-z0-9_]+[*<]?/)) { t = substr(rest, RSTART, RLENGTH); rest = substr(rest, RSTART + RLENGTH); if (t !~ /[*<]$/) print "N\t" f ":" FNR "\t" t }
     rest = $0
-    while (match(rest, /MSKIT_?[A-Z]+[0-9][0-9][0-9]/)) { t = substr(rest, RSTART, RLENGTH); rest = substr(rest, RSTART + RLENGTH); sub(/_/, "", t); print "M\t" f ":" FNR "\t" t }
+    while (match(rest, /MSKIT[A-Z]+[0-9][0-9][0-9]/)) { t = substr(rest, RSTART, RLENGTH); rest = substr(rest, RSTART + RLENGTH); print "M\t" f ":" FNR "\t" t }
   }' $(cat "$work/docs.lst") > "$work/docs.tsv"
 
 awk -v dir="$work" -F'\t' '
@@ -125,6 +147,8 @@ awk -v dir="$work" -F'\t' '
   function problem(m) { print "docs-check: " m; problems++ }
   FILENAME == dir "/properties" || FILENAME == dir "/items" { known[$1] = $2; what[$1] = (FILENAME == dir "/items" ? "item" : "property"); order[++n] = $1; next }
   FILENAME == dir "/codes" { code[$1] = $2; corder[++nc] = $1; next }
+  FILENAME == dir "/diagnostics" { dwhere[++nd] = $1; dcode[nd] = $2; dlink[nd] = $3; next }
+  FILENAME == dir "/oldspelling" { o = $2; sub(/_/, "", o); problem($1 ": " $2 " is the old spelling of " o); next }
   FILENAME == dir "/paths" { exists[$0] = 1; next }
   $1 == "S" { slug[$2 "#" $3] = 1; next }
   $1 == "D" { if ($2 == "docs/reference/properties.md") documented[$3] = 1; else documentedCode[$3] = 1; next }
@@ -136,6 +160,16 @@ awk -v dir="$work" -F'\t' '
   END {
     for (i = 1; i <= n; i++) if (!(order[i] in documented)) problem(what[order[i]] " " order[i] " (" known[order[i]] ") has no row in docs/reference/properties.md")
     for (i = 1; i <= nc; i++) if (!(corder[i] in documentedCode)) problem("code " corder[i] " (" code[corder[i]] ") has no section in docs/reference/codes.md")
+    for (i = 1; i <= nd; i++) {
+      c = dcode[i]; h = dlink[i]
+      if (c == "-") { problem(dwhere[i] ": a <Warning>/<Error> without a Code"); continue }
+      if (c ~ /^MSKIT[A-Z]+[0-9][0-9][0-9]$/) { want = "$(MSKit_CodesHelpBaseUrl)#" tolower(c); anchor = tolower(c) }
+      else if (c ~ /^%\([A-Za-z_][A-Za-z0-9_.]*\)$/) { want = "$(MSKit_CodesHelpBaseUrl)#$([System.String]::Copy(\047" c "\047).ToLowerInvariant())"; anchor = "" }
+      else continue
+      if (h == "-") problem(dwhere[i] ": " c " has no HelpLink; set HelpLink=\"" want "\"")
+      else if (h != want) problem(dwhere[i] ": " c " has HelpLink=\"" h "\"; expected \"" want "\"")
+      if (anchor != "" && !(("docs/reference/codes.md#" anchor) in slug)) problem(dwhere[i] ": HelpLink anchor #" anchor " has no heading in docs/reference/codes.md")
+    }
     relative = 0
     for (i = 1; i <= nl; i++) {
       split(links[i], l, "\t"); src = l[2]; ln = l[3]; base = l[4]; target = l[5]
@@ -152,5 +186,5 @@ awk -v dir="$work" -F'\t' '
       if (anchor != "" && dest ~ /\.md$/ && !((dest "#" anchor) in slug)) problem(src ":" ln ": link " target " names a heading that does not exist")
     }
     if (problems) { print "docs-check: " problems " problem(s)"; exit 1 }
-    printf "docs-check: %d properties and items, %d codes documented; %d relative links resolve\n", n, nc, relative
-  }' "$work/properties" "$work/items" "$work/codes" "$work/paths" "$work/docs.tsv"
+    printf "docs-check: %d properties and items, %d codes documented, %d diagnostics with a HelpLink; %d relative links resolve\n", n, nc, nd, relative
+  }' "$work/properties" "$work/items" "$work/codes" "$work/diagnostics" "$work/oldspelling" "$work/paths" "$work/docs.tsv"