- Exiled from Continuity: My Little Pony: Friendship is Magic, Jem and the Holograms, and Clue. The universe of the former is obviously incompatible with the other titles (though the editor in charge of Revolution said that things could change); in the case of Jem, IDW staff apparently consider them to take place in the same universe, but crossovers are unlikely to happen for reasons of tone. References to Jem have started to show up in the background of other titles, however- Ian Noble has a Misfits poster in his room. Much like Jem, the Clue comic book exists in the background of the universe. The Dungeons & Dragons title has also been left out, likely because it'd be way too difficult to tie them in with everyone else.
- This also applies to the A Real American Hero, Transformers vs. G.I. Joe, and Beast Wars series, excluded for being incompatible with the other Transformers and G.I. Joe titles (though Transformers vs. G.I. Joe has finished anyway).
- Aw Yeah Revolution!, being a parody of the universe, isn't canon either.
- Screwed by the Lawyers: The Inhumanoids were going to be the monsters in G.I. Joe vol. 5. Then when IDW sent the script into Hasbro, it turned out they couldn't use them because Hasbro had let their trademarks expire. Thus, they had to be rewritten into the Fatal Fluffies.
Trivia / Hasbro Comic Universe