I'm using phpBBAuth as an authenticator.
Now I'm trying to understand how this impacts groups. And maybe ACL.

As far as I understand, by default, all groups from PhpBB are available (given that there is a user who is in them).
Are they available in all channels?
If I define a mumble group with the same name, will it overwrite the phpBB group?
If I exiplicitly remove users from one of these groups in an subchannel, will it work?
Are groupnames case sensitive?
Does whitespace in groupnames matter?