LeaVerou/regexplained — pull request #1 by mathiasbynens (2012-05-31 05:08:06+00:00)
Title: Update dfn@title for `\s` to match ES 5.1 and Unicode 6.1

http://es5.github.com/x15.10.html#x15.10.2.12:

> The production `CharacterClassEscape :: s` evaluates by returning the set of characters containing the characters that are on the right-hand side of the [`WhiteSpace` (7.2)](http://es5.github.com/x7.html#x7.2) or [`LineTerminator` (7.3)](http://es5.github.com/x7.html#x7.3) productions.

http://es5.github.com/x7.html#x7.2:

> ECMAScript implementations must recognize all of the white space characters defined in Unicode 3.0. Later editions of the Unicode Standard may define other white space characters. ECMAScript implementations may recognize white space characters from later editions of the Unicode Standard.