I have a site catering to multiple clubs, and each club has administrators who maintain a database of club members. I want to limit site registration only to members who have explicitly been added to the club's database. How do I go about auto-generating and sending out registration links to members as they are added to the database? In other words, I want registration to be initiated only by club administrators.
To limit registrations to people already in the database, you will need some way to identify them.