Am 25.02.2011 00:43, schrieb Rasmus Villemoes:
> Joseph Wright <[log in to unmask]> writes:
> 
>> Handy list. I'll have to look through by hand as what I need to know is
>> direct use of expl3 material (as I know about fontspec, simply requiring
>> it is not so much of the issue as subsequently \ExplSyntaxOn within the
>> package).
> 
> The subset with at least one occurence of \ExplSyntaxOn is not so big:

I think you should also search class (*.cls) files. Furthermore,
\ExplSyntaxOn is executed by \ProvidesExplPackage/Class/File.