Comment 7 for bug 868653

I wonder if it would make more sense to put this on the user permission editor form rather than the patron registration form. My reasoning is that adding secondary permission groups is something that seems likely to be done only for staff users, and since you always have to use the UPE form when adding a staff user (in order to set working locations), putting it there removes a potential source of clutter on the registration form.

To be clear, this comment is meant only as food for thought; I don't feel strongly that the registration form is necessarily the wrong place for secondary groups, since one does set the primary profile there.