Wikimedia Bugzilla is closed!

Pages that list templates and show how those templates look appear in all the
categories contained in those templates. This can be annoying and breaks the
semantics of those categories. (For example, a page that lists and displays the
different deletion templates might get included in the "pages for speedy
deletion" category because it has a speedy deletion template on it. The page is
obviously not meant to be deleted, but automated tools that rely on the meaning
of the category might get the wrong idea.) 

It would be nice to have a way to invalidate some of the category transclusions.
I don't know how the parser works, but if it simply collects the categories in
the wikitext into some list, then it would be trivial to clear that list when
the parser encounters some magic word; that way you can put something like
__clearcategories__ to the end of the page and then the real categories would
follow.