Thanks, that was very helpful. I was basically hoping to find a document that covered the second half of your comment.

I don't have any concrete plans to work on Lemmy so far but I was thinking about the possibility of tags for posts (especially but not only NSFW ones) and filters that work on those tags. Of course if you can rely on the author to tag everything that would probably just be some new extension to the post object but I was considering the option of something similar to the tag systems on adult image or story hosting sistes or Steam where third parties can add, modify or remove tags/metadata about the content in some way too.

It sounds to me as if something like that would probably be modelled similar to top-level comments in the AP ecosystem (but of course displayed and used differently).