Most rooms are public. Anyone on the system may get into a public room.
Private rooms may take several forms:
 
 Hidden: to gain access to this type of room, a user need only know
the room's name. No hints are given by the system.
 
 Passworded: same as hidden but the user must also know a password
to get access.
 
 Invitation-only: users may only gain access to this type of room if
an Admin gives it to them. 
 
 Personal: this type of room acts as a user-specific "mailbox."
  
 Once a user has access to a private room, it shows up on the known
rooms list and acts the same as any other room. Admins may kick users out
of any type of private room, and out of excludable rooms.  Please also keep
in mind that Admins have access to ALL private rooms.
 
 Before making it private, think about it. Does it really NEED to be private?