User blog comment:MakeShift/The Crisis and its impact on the Arrowverse Wiki/@comment-25054842-20200123152310/@comment-2054358-20200123163156

Doom Patrol started off as a spinoff of Titans. There is even a Titans episode starring them. It should have been Earth-9 but the Arrowverse writers decided to put the Doom Patrol on Earth-21. So I don't think we could cover Doom Patrol.