Currently, it looks like Plex can restrict content for users based on a collection of tags (positive tagging = user can see everything with the following labels). I would like to suggest negative tagging for ratings and keywords (negative tagging = user can see everything EXCEPT items with these tags). I think for many people who cannot take time to tag their entire library, this could significantly reduce time it takes to categorize, filter, and potentially restrict their libraries.
Existing Request:
https://forums.plex.tv/discussion/150844/feature-request-plex-home-inverse-filter-blacklist/p1
Early 2021 clean-up: duplicate/implemented