A is for Anon 7. Anon as in annoying
B is for Ben, who helped tend bar in Ten Forward and liked making friends with junior officers.
C is for Chuckles. If you have to ask. Leave immediately.
D is for Deela, the hyperaccelerated Queen of the Scalosians.
E is for Emergency Medical Hologram.
F is for Ferengi dress codes. Men wore anything. Women wore nothing.
G is for Gods. Mostly pretenders and wannabes.
H is for Hikaru Sulu
I is for Internal Security, handled in extreme cases by agents of Section 31.
J is for Johnny Pikard. Pompous bald dude with squirelly accent. Says he's from France but sounds British. Must be on the lamb from someone.
K is for Klingon
L is for Laser Pistols. At least some Starfleet crews in the Prime timeline circa 2250 used them to great effect.