Board Thread:Support Requests - Designing Your Wikia/@comment-25653892-20151122173616/@comment-25876067-20151122181434

The custom404-* one looks like it will show up when you visit a page that doesn't exist.

The customcssprotected and customjsprotected are what show up when you try to edit someone else's personal css or js page.

Not sure for the other two.