[Mediawiki-l] Check if page belongs to a certain category? (skin level)

[Adam Meyer]

If there a way to check if a page is part of a certain category from  
the skin level.

I know it is probably unorthodox, but 90% of what I do on my wiki is,  
but I need a new tab to appear only if an article is part of certain  
categories. Right now I have the tab, but it appears on every page.

Thanks,
-Adam