I have a start to that, in the form of my block list:-). Of course it is highly tuned to my personal interests, and does not do full "categorization" beyond merely "is in said list" vs. "is not in said list", plus it only helps me personally rather than e.g. someone fleeing Reddit due to their continual messes. In that way it is like recommending a book to someone, vs. making the entire Dewey Decimal or other system to classify books in a manner that makes retrieval easier for other people.

Moreover, I think the main part would be to allow community self-selection - e.g. if I call something by a term, that is me putting that label onto them, while if they choose it for themselves it seems much more friendly?

Anyway, I thought lists of communities were already widely available? The trick might rather be to keep them maintained - e.g. to open up a wiki page, except that starts to involve who will host it, and like everything else Fediverse-related, who will fight off the hostile actors who keep uploading CP to it? (see e.g. this post describing yet another instance closing b/c of such attacks)

These matters are not so "simple" - e.g. would a far-right community be "heroes" or "genocidal terrorists", or both depending on who you ask? In my own personal block list, I get to make my own determinations (bonus: at a low-resolution level of merely "see" vs. "not see" such content, without having to think any more about it!:-P), but attempting to go beyond that... really does require some consensus-building skills. OR we could hope for UI tools that allow people to choose their own personal preferred method of accessing content across the Fediverse, which side-steps all that and keeps it at the level of unique, personal preferences.

The detraction is that if too rigidly applied, it creates echo chambers. On the other hand, please feel free to look at all the CP, pics of food, and descriptions of sportsting that you like, yet *I* do not want to waste my time with such, and if the only choices are "All" or "None", then I want the option to choose the latter, at least sometimes. I would presume that others think likewise.