Yes, there is a table on this page, if you expand the “Project Registration” bit:
https://pt8.paratext.org/help/registry/registration/
Projects that are not registered fall under the “Basic Tier”.
Users registered without an e-mail address cannot be administrator or consultant of a project. Of course, since they don’t have a login to the Registry without an e-mail address, they cannot use any of the features of the Registry either; but they can associate their account with an e-mail address when they sign up in the Registry using their Paratext 8 code.