A is for the Aldebaron Colony, Elizabeth Dehner's posting before joining the Enterprise crew in 2265.
B is for Breen Confederacy.
C is for Cardassian Union.
D is for Denobulan face sac.
E is for Exeter. Enterprise's sister that was infected with a very nasty bacteria that killed the crew.
F is for Farragut
G is for Gul Dukat
H is for Horta
I is for Illicit trade in biomimetic gel. A major offense under late 24th century Federation law.