diff --git a/spec.md b/spec.md
index 41ee258..d918993 100644
--- a/spec.md
+++ b/spec.md
@@ -39,6 +39,10 @@ Keys do not require quotes around them. Unquoted keys can consist of any UTF-8 c
 - [Whitespace](#whitespace)
 - `.` full stop (period)
 - `=` equals
+- `[ ]` square brackets
+- `{ }` braces
+- `'` single quote
+- `"` double quote
 
 Optionally, a key can be surrounded by single quotes `'`. This removes all of the above limitations.
 
@@ -101,6 +105,8 @@ This results in the following JSON output:
 }
 ```
 
+#### Escaping
+
 The following standard escape characters are supported:
 
 - `\\` backslash
@@ -113,11 +119,12 @@ The following standard escape characters are supported:
 { foo = "hello\nworld" }
 ```
 
-You can also include any Unicode character using an `\uXXXX` escape code.
-`XXXX` must be replaced with exactly 4 hexadecimal digits.
+You can also include any Unicode character using an `\u{XXXX}` escape code.
+`XXXX` must be replaced with 1–6 (inclusive) hexadecimal digits.
+Alphabetic characters are case-insensitive.
 
 ```corn
-{ foo = "\u2603" }
+{ foo = "\u{0061}" }
 ```
 
 ### Integer
@@ -138,6 +145,24 @@ Underscores cannot be the first or last characters in a value.
 }
 ```
 
+Four bases are supported:
+
+- Decimal, with no prefix.
+- Hexadecimal, using a `0x` prefix.
+- Octal, using a `0o` prefix.
+- Binary, using a `0b` prefix.
+
+```corn
+{
+  dec = 10
+  hex = 0x1a
+  oct = 0o77
+  bin = 0b101010
+}
+```
+
+Each base supports the same pos/neg sign and underscore rules.
+
 ### Float
 
 Floats are double-precision (64-bit).
@@ -318,14 +343,16 @@ this is handled as an undeclared input.
 
 Inputs with values of type [string](#object) can be interpolated inside string values.
 
-The input is referenced in the standard manner within the double quotes `""`, and standard input reference rules apply.
+The input is referenced using a `${name}` syntax within the double quotes `""`. 
+The standard input reference syntax `$name` is invalid for interpolation.
+Standard input reference rules apply.
 
 ```corn
 let {
   $subject = "world"
 } in {
   // evaluates as "hello, world"
-  greeting = "hello, $subject"
+  greeting = "hello, ${subject}"
 }
 ```
 
@@ -334,12 +361,13 @@ the dollar should be prefixed with a backslash `\`.
 
 ```corn
 {
-  // evaluates as "hello, $subject"
-  greeting = "hello, \$subject"
+  // evaluates as "hello, ${subject}"
+  greeting = "hello, \${subject}"
 }
 ```
 
-Non-string input types are not supported.
+Interpolation of both string and integer types is supported. 
+Interpolation of other types is invalid.
 
 ### Object merging
 
@@ -460,7 +488,7 @@ The following characters are valid whitespace:
 
 Any quantity or combination of the above characters is permitted, so long as it abides by the rules described below.
 
-Whitespace is almost entirely optional. It is required in the following places only:
+Whitespace abides by fairly standard rules. It is required in the following places only:
 
 - When an integer or float follows another integer or float, whitespace must be included between them:
 
@@ -486,7 +514,7 @@ Whitespace is almost entirely optional. It is required in the following places o
   }
   ```
 
-- When a value is followed by a key, whitespace must be included between them.
+- When a key follows a value, whitespace must be included between them.
 
   ```corn
   {
@@ -497,6 +525,18 @@ Whitespace is almost entirely optional. It is required in the following places o
     foo = 4bar = 4
   }
   ```
+  
+- When a literal token follows another literal token, whitespace must be included between them.
+
+  ```corn
+  {
+    // valid, tokens are separated by whitespace
+    foo = [ true false ]
+    
+    // invalid, tokens are not separated by whitespace
+    foo = [truefalse]
+  }
+  ```
 
 Whitespace cannot exist inside key or value tokens, unless part of whitespace inside a string literal:
 
@@ -513,7 +553,7 @@ Whitespace cannot exist inside key or value tokens, unless part of whitespace in
 }
 ```
 
-Based on these rules, Corn supports a very compact syntax. The following is entirely valid:
+The following "condensed" example is valid:
 
 ```corn
 {
@@ -524,10 +564,9 @@ Based on these rules, Corn supports a very compact syntax. The following is enti
   five={foo=null bar=null}
   six={foo={} bar={}}
   seven={foo=[] bar=[]}
-
   eight=["foo""bar"]
-  nine=[truefalse]
-  ten=[nullnull]
+  nine=[true false]
+  ten=[null null]
   eleven=[[][]]
   twelve=[{}{}]
 }
@@ -536,7 +575,7 @@ Based on these rules, Corn supports a very compact syntax. The following is enti
 And since newlines and indentation are optional too, this can be condensed further into:
 
 ```corn
-{one={foo="bar" bar="foo"} two={foo=1 bar=2} three={foo=1.0 bar=2.0} four={foo=true bar=false} five={foo=null bar=null} six={foo={} bar={}} seven={foo=[] bar=[]} eight=["foo""bar"] nine=[truefalse] ten=[nullnull] eleven=[[][]] twelve=[{}{}]}
+{one={foo="bar" bar="foo"} two={foo=1 bar=2} three={foo=1.0 bar=2.0} four={foo=true bar=false} five={foo=null bar=null} six={foo={} bar={}} seven={foo=[] bar=[]} eight=["foo""bar"] nine=[true false] ten=[null null] eleven=[[][]] twelve=[{}{}]}
 ```
 
 Writing Corn in the style of the above two examples is not recommended.