Thread:Sakaros/@comment-33320521-20181217011026/@comment-104549-20181217012125

Hey Nate. I removed it because it's what's sometimes called a "duplicative category"—that is, a category that is less specific than another category applied. Put another way, per the Categorization Policy, if Category A is a subcategory of Category B, then A is applied to a page and B is not.

For the concrete example here, "Desert planets" is a subcategory of "Planets". All desert planets are planets, but not all planets are desert planets. Since "Desert planets" has been applied to Khamsinad, "Planets" shouldn't be.