I'm not quite certain why, but even administrators are forbidden from moving category pages around. The case I have is "Category:Organization", which in particular I wished to history merge with Category:Organizations. I noted the lack of a button at the top, and when I tried Special:MovePage, no go either.
This right should not be forbidden within user permissions, only within guidelines (which ideally, categories wouldn't be moved unless necessity demanded it). I can understand the potential reasoning (e.g., moving categories doesn't move the articles), but that is why guideline should rule here and not technical specifications; we can decide if and when we'd like our categories to be moved around.
On a further note, are there any other namespaces which are move forbidden? There shouldn't be, but I'd like to establish whether there are any others, simply because I'd like to request that the technical limitations on those also be lifted. --Sky (t · c · w) 19:14, February 10, 2010 (UTC)
P.S.: I seem to be able to recall at some point in our far past the ability to move categories around, which suggests that this is a Wikia limitation…