A is for Andorian incidents.
B is for Betelgeusians. They were seen just once in the franchise in the background of TMP, but looked very interesting.
C is for Camp Khitomer. Site of an historic peace conference between the Federation and the Klingon Bastards.
D is for Daring. Famous Starfleet captains tend to have this as one of their most notable qualities.
E is for Eymorg. Givers of pain and delight.