Thread:KingCannon/@comment-7218858-20170706023832/@comment-25501246-20170706163429

To be canon means to be part of the main continuity, which is the MHA manga. Anything outside that (anime fillers, movies, games) is non-canon by default.

That is, they have to make an appearance in the manga, or at least be confirmed by Horikoshi that they exist in his story in order to be considered canon.

The only "canon" thing from Illegals so far is Trigger, and even then it's just half-canon, as Horikoshi has gone out of his way to not use the drug's name.