content tagging

Hi guys, I've set my community to prevent unregistered user to use the search function, but I would also like to restrict the use of Filters and Tag filtering to members only. I've seen there's nothing about that among XF permissions and I couldn't even find any add-on for this or anything...

I've enabled tagging on one of my forums to better understand how it works and to get a handle on permissions. One of the things that has quickly become apparent is that similar tags, for example singular and plural versions of words, or words that are interchangeable and mean the same thing...