Board Thread:Clean up Concerns/@comment-366087-20160507223224

HOLD THE PRESSES! STOP adding categories to categories—also known as making Subcategories—until you READ THIS.

Allow me to teach you how to make subcategories with WikiMedia. Meaning Wikia, Wikipedia, and other wiki-based sites.

First, it is not as simple as opening a page and adding a category, like is done for Articles. With articles, you add a category and it appears at the bottom of it, and that page appears on the category page. Done deal.

But that is not how you make a sub-category.

Say you have Cat:A and you wish to make Cat:B sub to it. You do not open Cat:A and add Cat:B. What you have to do is open Cat:B and add Cat:A to Cat:B. How can you tell? Open the category which is the "parent" Cat, look for a section just above the pages, under the pictures, which says "this category includes the following subcategories" and see if the subcat you meant to add is listed there. If not, you did it wrong, Undo and reverse. Because Sub-cats are NOT listed at the bottom of a parent-cat, they are listed in that section mid-page, and any cats at the bottom of a category page are actually parent-cats that cat page is sub-to.

Also, ensure the SAME category is NOT at BOTH the bottom AND in the Sub-cat area. If you have that, someone, a couple someones, messed up. A category cannot be both Parent and Sub. One has to go.

Second, when making subcategories, what you have to do is ask "is everything in this subcat, ALSO a part of the parent cat?" If the answer is "NO", do not add it.

For example: "Are ALL Star Trek Villains, Tyrants?" No. So you don't make Tyrants sub to Star Trek. While you're doing that, reverse the question, "Are ALL Tyrants, Star Trek villains?" Answer is still "No", so you don't reverse the parent/sub cats either.

Another example: Perverts and Pedophiles. Which should be subcat to which? Are ALL perverts, pedophiles?" No. "Are ALL pedophiles, perverts?" Legally, yes. So the parent category would be Perverts and the sub-category is Pedophiles. Which means you open "Pedophiles", add "Perverts", then double-check by going to Perverts and looking for the sub-cat section to make sure "Pedophiles" is listed. If it is, you did it right.

Same situation for Perverts and Rapists… not all perverts are rapists, but all rapists are perverts… see how it works?

Again, if the answer to the qualify-question is "No", then don't make the sub-cat no matter how much you think it should be.

The only exceptions to this are categories automatically add by templates, like the   Template adds whatever page it is on, cat or article, into the Mature Category. That's a case of site management more than Parent/Sub-cats (and really should be hidden from non-admins).

Read: which links you to
 * Creating sub-categories
 * Wikimedia.org help about Subcategories 