Board Thread:Questions and Answers/@comment-20509806-20131119210349/@comment-1038387-20131119213325

They are presented as one. Year One (which also takes place in New Earth), A-S B&R, TDKR and DKSA, plus the occasional Earth-31 appearance during Countdown, all take place within "Earth-Miller", "Earth-DKR", or, as it's officially known, "Earth-31".

Your "evidence that they are in different continuities" isn't that, it's just continuity erors, character mistakes, the lot. They're goofs. Goofs show up all the time, including in the mainstream universe. That doesn't make stories with mistakes from different universes.

The first thing I learned at contemporary literature was "if the publisher says it's X, it's X, no matter what you find inside." The Powers That Be say it's one big universe, so it is.