It would be great to have an extension to handle user registrations through an invitation system. This would help making a "semi-private" forum.
When activated, no new registrations are allowed but each member would have a number of invitations available (previously set up in ACP) to invite other friends to join the forum.
Invitations could be sent by email with a registration key (or something similar).
Additional features or sub-extensions could be:
- Ability to set up the number of invitations available and the period of time for their availability.
- Ability to customise the "Invitations only" message in ACP.
- Ability to keep track of invitations (who invited who) and show it in profile (Invited by X).
- Ability to restore available invitations for all or specific users every x time.
- Ability to set the invitation key to be only available for a specific amount of time.