Many of the Alliance’s generals and commanders are from Alderaan. Not all of Alderaan’s population are active members of the Rebellion, but most support the cause.
While at an Alderaan site: adds 1 to your Force drains there, is forfeit +1 (and power +1 if your general is on Alderaan) and, once during each of your deploy phases, may deploy one site to Alderaan from Reserve Deck; reshuffle.