Board Thread:Support Requests - Getting Technical/@comment-32452702-20170707222749/@comment-1757994-20170708192405

You can set up different namespaces, like User: and Project:, but with whatever names you select. If your wiki is small (like less than a few hundred pages), there may not be a real need for separate namespaces.

Categories are essentially single-valued properties (it's there or it isn't) that can be assigned to a page. They don't really change anything about the page other than the ability to get a list of them by going to the appropriate Category: page.