A is for Alpha Cygnus IX, where Sarek of Vulcan once concluded an historic treaty. B is for Betazoid wedding ceremonies. The wedding party is naked. Saves on expensive dresses and tuxedos. C is for the Cardassian-Federation War of the 2350s and 2360s. D is for dilithium miners. You'd think that they could afford nicer digs (pun intended).