Board Thread:Support Requests - Community Management/@comment-5650583-20150302150119/@comment-26009167-20150302193007

Personally, I just try to make sure the categories are relevant and useful in some way. I like to think of categories as descriptors, and that means that if a category can't describe something, then it's to be deleted or merged.

Actually, and this is still me personally, categories are relevant as long as they described something at a any point. For example, transgender people can categorize their page(s) on a wiki of mine under both "Male Users" and "Female Users", as long as both applied at some point. Although if the rules of the Wiki say not to do it as I do, you may wish to change the now-non-descriptive category of the page to include the word "Former". (i.e. "Former Male" or "Former Female")

Categories don't have to be factual though. You could have a category for "Funny Content", even though "Funny" by itself is to be determined by the reader. Generally if you do that, it should be something that the community at large generally will agree with. (For example, memes can be funny!)

This is all just how I personally do it. I don't have any advice other than that useless categories should go.