AFAIK = As far as I know
AFK = Away from keyboard
ASAP = As soon as possible
A/S/L? = Age/sex/location?
B4N = Bye for now
BAK = Back at the keyboard
BAS = Big a** smile
BBIAB = Be back in a bit
BBL = Be back later
BBN = Bye bye now
BBS = Be back soon
BFD = Big f***ing deal
BFN = Bye for now
BRB = Be right back
BTA = But then again...
BTDT = Been there, done that
BTW = By the way
CICO = Coffee in, coffee out
C&G = Chuckle and grin
CNP = Continued in next post
CRB = Come right back
CRBT = Crying real big tears
CU = See you
CUL = See you later
CUL8ER = See you later
CYO = See you online
DBA = Doing business as
DL = Dead link
DIKU = Do I know you?
DITYID = Did I tell you I'm distressed?
DTRT = Do the right thing
DWB = Don't write back
F2F = Face to face
FAQ = Frequently-ask question(s)
FWIW = For what it's worth
FYI = For your information
GA = Go ahead
FISH = First in, still here
GAL = Get a life
GL = Good luck
GMAB = Give me a break
GMTA = Great minds think alike
GTRM = Going to read mail
GTSY = Glad to see you
HAGN = Have a good night
HAND = Have a nice day
HIG = How's it going
HT = Hi there
HTH = Hope this helps
IAC = In any case
IAE = In any event
IC = I see
IHA = I hate acronyms
IHU = I hear you
IM = Immediate message
IMCO = In my considered opinion
IMO = In my opinion
IMS = I am sorry
IOW = In other words
IRL = In real life (that is, when not chatting)
IYSWIM = If you see what I mean
JIC = Just in case
JK = Just kidding
JTLYK = Just to let you know
KIT = Keep in touch
KWIM? = Know what I mean?
L8R = Later
L8R G8R = Later gator
LHO = Laughing head off
LOL = Laughing out loud
LTM = Laugh to myself
LTNS = Long time no see
LTR = Long-term relationship
LULAB = Love you like a brother
LULAS = Love you like a sister
MorF = Male or female
MOSS = Member of the same sex
MOTOS = Member of the opposite sex
MTF = More to follow
MUSM = Miss you so much
NP or N/P = No problem
NRN = No response necessary
OIC = Oh, I see