AFC = Alliance flag carrier
HFC = Horde flag carrier
FC = flag carrier
EFC = enemy flag carrier
WSG = Warsong Gulch. note: WG typically means Wintergrasp.
AB = Arathi Basin
GG = Grom'gol OR good game. If used within a BG it means good game.
pot = potion. if someone "potted" or used a "pot" it typically means health pot but can mean mana, speed, or even free action potion.
speed pot = speed potion
hp = health
WC = Wailing Caverns. located in the barrens, southwest of The Crossroads.
VC = Deadmines, or Van Cleef. located in westfall, southwest of Sentinel Hill.
DM = Deadmines OR Dire Maul. typically denoted as Dire Maul but a few people decide not to use the term VC for the Deadmines...
SFK = Shadow Fang Keep. located in western Tirisfal Glades.
BFD = Black Fathom Deeps. located in northwest Ashenvale.
RFC = Ragefire Chasm. located in Orgrimmar.
RFK = Razorfen Kraul. located in the southern barrens.
RFD = Razorfen Downs. located in the southern barrens.
gnomer = Gnomeregan. located in northwestern Dun Morogh. for horde, see this
Quest
rev = Revelosh, the first main boss in Uldaman.
Ulda = Uldaman
WTF = way to fight. someone is congratulating a well played situation by someone.
OOM = out of mana
AFK = away from keyboard. typically denotes a long period of time from being at the computer.
BRB = be right back. typically denotes a short period of time from being at the computer.
BBL = be back later. typically denotes that you will be back later in the day, but are leaving for now.
GTG = good to go. used mainly with raids to let people know that you're ready.
G2G = got to go. typically denotes that you are leaving.
sry = sorry
TBH = to be honest
OMG = oh my god
IAML = i'll add more later
IAML