Since 2.5.0 you can now let user register with just an email address. They don't have to enter a username. A username will be generated upon registration and is not used anymore [...]
registration archives
b3_disable_action_links()
Disable the action links shown below a custom form.
b3_redirect_after_register()
A filter to redirect a user to a custom location after registration.
b3_reserved_usernames()
With this filter you can add/change the reserved user names.
WordPress registration page is redirecting to custom form
If you didn't set the setting to force your own pages but still find your registration page is redirecting, this might offer an answer.
Localhost development
If you're a developer, you are probably developing your site locally. The we have some good news for you. We have thought of that [...]
b3_do_before_first_last_name()
This hook is used to add something right before the first/last name fields.
b3_do_after_first_last_name()
This hook is used to add something right after the first/last name fields.
b3_do_after_submit_registration_form()
This hook fires immediately after the submit button on a registration form.
b3_message_above_registration()
With this filter you can message above on the registration form.
b3_message_above_login()
With this filter you can change/set/remove the message above on the login form.
b3_privacy_text()
Filters the privacy text on the registration form
b3_localhost_email()
With this filter you can set a pre-filled email address on the registration form.
b3_localhost_username()
With this filter you can set a pre-filled username on the registration form.
b3_do_before_submit_registration_form()
This hook fires immediately before the submit button on a registration form.