Thread:Paperluigi ttyd/@comment-4839099-20120527154113/@comment-3235402-20120529162843

...or move them out. However, this is just because of how the system of MediaWiki works. A page's categories are stored in the page in the form of invisible links (type a colon before the word "Category" in Source Mode to make it a clickable link and not a category) that the system just sticks in the category bar. To rename a category would mean that either none of those pages would be in the new-name category, or it would have to edit all the pages, and if it's a big category, then it may overload the server.