A is for Rene Auberjonois.
B is for Robert Beltran.
C is for Cirroc Lofton.
D is for Dominic Keating.
E is for Eddie Paskey.
F is for Vic Fontaine.
G is for Gomtuu.
H (returning to this round's list of actors) is for Majel Barrett's birth name, Majel Leigh Hudec.
I is for Ian Alexander.
J is for James Montgomery Doohan.
K is for Winrich Kolbe, director of "Siege of AR-558" and Vietnam vet.
L is for Mark Lenard.
M is for Colm Meaney.
N is for Tawny Newsome.
O is for Orla Brady, who figured rather prominently in PIC.
P is for John Paragon, who played the Syndicate boss Thadial Bokar in a couple of episodes of DS9.
Q is for Quint Strack, a rather obscure extra appearing in ENT: "Broken Bow."