Organizers can create events with
an open headcount or
a fixed number of places. Members can sign up once and withdraw before the event starts. A withdrawal immediately frees a place. Members see the headcount and their own response, and organizers can view the attendee list.
Upgrade from Beta 1 in the XenForo Admin CP. Under
Booking Manager permissions, grant members
Sign up for booking events and organizers
Manage events and view attendee lists. Then open
Bookings → Event sign-ups → Add event. Leave capacity blank for an open headcount.