>>6343291Looking over this
https://en.wikipedia.org/wiki/List_of_DC_Multiverse_worldsit appears I was incorrect.
Unless Watchmen was an unnamed parallel Earth pre-crisis. But it never crossed over with anything in the way that Squadron Supreme did for Marvel (where even stuff like the Marvel vs Capcom games are canon to Marvel multiverse). So I guess, by the rules established, Watchmen is fair game.
