bug: documentation uses unsupported (but TAL spec) modifier

I noticed this today in the petal documentation:

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omit-tag

Abstract

   <tag tal:omit-tag="EXPRESSION">Some contents</tag>
Example

   <b tal:omit-tag="not:bold">I may not be bold.</b>
If not:bold is evaluated as TRUE, then the <b> tag will be omited. If  
not:bold is evaluated as FALSE, then the <b> tag will stay in place.

Why?

omit-tag statements can be used to leave the contents of a tag in  
place while omitting the surrounding start and end tags if the  
expression which is evaluated is TRUE.

TIP:

If you want to ALWAYS remove a tag, you can use omit-tag="string:1"

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i've discussed this before, but "not:" is a TAL modifier that isn't  
in petal

i just wanted to bring this up again, as following the docs in this