The meaning of that is that there is no central authority nor uniformity for antifa or BLM groups.

Everybody can start their own antifa group because all that takes is opposing fascism, that's the only unifying factor there.

It's the same with BLM: It's not some kind of ideology with international governing institutions, it's a call to a cause very much like antifa.

It's simply opposition to fascism/police violence without even much unity on with what to replace it.

BLM has a political action committee.

https://www.politico.com/news/2020/10/09/black-lives-matter-...

https://www.blmripac.com/

I'm going to go one step further. Anyone can be antifa, even the facists. Same with blm and racists. There's absolutely no governing body, and from what I've seen, there's at least a visible portion of the antifa who care little for facism opposition and more for wrecking shit.

That's the catch with these movements. Any description of them is by necessity a generalization.