I'm redesigning my blog and I'd like to display a list (or just the latest) post that is assigned to multiple categories.
I know about the category__and function, but so far as I can tell it requires you to specify which categories your post must belong to (e.g., show posts in categories 2 and 6).
What'd I'd like to do is show any posts that belong to more than one category, but I can't find anything on how to do this in the codex or the forums.
Is there a way to use category__and to ask for a list of all posts assigned to multiple categories?
Is there another function that would do this instead?
Alternatively, what might be the best way to go about writing a hack to do this?