有哪些可能的AspNet IdentityResult错误？

I've googled and can't find anywhere a list of possible errors, e.g. "Email xyz is already taken." (I know that is one definitely). "Name xyz is already taken." is another (for the username). I'm using Microsoft ASP.NET Identity 2.0, not version 3 on Github. They seem to be just simple strings and don't seem to have error codes or anything. I've had a look through the code on Codeplex also and there doesn't seem to be a clear list anywhere, just some vague fragments in unit tests.I've googled and can't find anywhere a list of