Board Thread:General Discussion/@comment-16581186-20161115131009/@comment-3423279-20161115191721

Sigh... you are just ignoring that this discussion has already been finished beforehand.

The four shows that are covered on this  wikia  are connected to each other or are confirmed by the creators to now be connected.

Arrow, Flash, Vixen, LOT, and now Constantine due to his appearances in Arrow.

As for Supergirl, as of now, she hasn't appeared on any of the above shows except one brief glimpse during the Season 1 finale and Barry saying "How long was I gone?" Being the only actual reference.

The other universes argument doesn't really apply, as Supergirl had only be referenced twice and as of now has had zero interaction with the Arrowverse shows apart from the Flash appearing for one episode.