Comment:
From http://lists.w3.org/Archives/Public/public-comments-wcag20/2006May/0120.html
Ensure that numerals or other look alike glyphs are not used in place of letters
There goes your l33tspeak, h4xorz! (\/\/C4G iz teh sux0r @nyw@y111oneoneone)
The working group does not consider leetspeak to be accessible. We have moved the advisory technique from SC 1.3.4 to SC 1.1.1, where it was changed into the following techniques and failures:
* Failure of SC 1.1.1 due to using look-alike glyphs to represent text without providing a text alternative.
* Providing text alternatives for strings where look-alike glyphs are used in place of letters (e.g. Leetspeak).
* Failure of SC 1.1.1 due to using ASCII art without providing a text alternative.
* Providing text alternatives for ASCII art.
We have also updated the note to the definition of non-text content so that it reads: 'This includes ASCII Art, which is a pattern of characters, and leetspeak, which is character substitution.'