a /limit function
Basically, the idea behind it is that you could set up a server, and with a command you could do this:
Basically, lets say you would have a server set up for only members of your clan.
what could you do is do something like /limit (Cheat) and it would only allow people with (Cheat) in their name to join.
Making a private server would make you have to say the password to each member of your clan who joins, so this could be a neat alternative.