It would be nice to be able to have users be automatically added to a waitlist if the session selected is full. This is how I see it currently User first needs to be able to view both open and fully booked sessions. The user selects a fully booked session and is presented with a waitlist button. The user clicks the waitlist button and is placed in a waitlist for that session, in the database I would see this as a waitlist table so that users can be added in order of registration or selection. If, A> a user cancels their booking then the system checks the waitlist table and moves the first user in the list for that session into the student role for that session or B> if the instructor increases max capacity for the session then the system checks the waitlist table and moves the appropriate number of users in order of registration into the student role for that session.