On 5.10.2012 14:11, MultilingualWeb-LT Working Group Issue Tracker wrote:
> Since we don't define anything for a blank allowedCharacters, I assume it means the blank pattern is evaluated and can't possibly match any character, so it means none is allowed. (which is a strange case).
> 
> Is it the proper interpretation?
+1
This is also consisten with XML Schema interpretation of the same case
(and there seems to be Xerces bug as well).
   Jirka
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