User blog comment:Archivist217/Expansion of Young Justice, if the series renews/@comment-99.37.159.160-20121125054900/@comment-1038387-20121127214527

The Batman Beyond series does not take place on Earth-12. It's officially a possible future of the mainstream universe, but essentially a self contained universe that borrows elements from New Earth and the DCAU.

Earth-12 is a universe in which a Batman that dresses like Terry (and communicated with Bruce) appears, but in the Countdown: Arena series, this world is expanded a bit - the Green Lantern is called Hal Jordan III (and there are only seven left in the entire universe). Now, Countdown: Arena is notoriously bad (both in story and art) and contradicted a lot by later works (including out very own YJ) but it was still considered canon. Much to everyone's dismay.

It was really, really bad.