Yeah. And I guess the thing is that I'm not sure fanfic truly can have a legal definition at all—laws can define what is copyright infringing, say, but works can infringe copyright without being fanfic, and be fanfic without infringing copyright, and some of those out of copyright canons have large and active fandoms, so the law doesn't seem especially helpful here.

It is a very elegant flowchart, though!