Thread:LucidPigeons/@comment-24758512-20160211152917/@comment-366087-20160212050945

Removals aside, the principle here is that when you add a Cat to a page, the page is placed *in* the Cat. The meaning is clear: this page belongs with all the things this Cat defines.

When you add a Cat to a CAT, it is reversed. The Added-Cat is *subset* to the existing-CAT. What is meant is "ALL in the Added are also defined by the Existing".

So in this case, Not ALL Villainesses are maternal. But ALL Maternals are Villainesses.

And that is how subcats are determined. "Are ALL in this Cat also defined by the Cat it is being added-to?" If "No", do not add it.