topi wrote:

I would like to combine Categories. Does there allready a solution exist?

Yes, I've seen this on Wikinews:

<DynamicPageList> category=August 14, 2005 category=Published notcategory=Disputed suppresserrors=true </DynamicPageList>

This produces a list of all articles that are in [[Category:August 14, 2005]] and [[Category:Published]] but not in [[Category:Disputed]].

See also http://meta.wikimedia.org/wiki/DynamicPageList

Timwi