ADCO A Dave Cowles Original
AFAIK As far as I know
AFK Away from computer keyboard (for wireless users)
AIM AOL Instant Messenger; also verb for FTP'ing files via AIM
ASAP As soon as possible
A/S/L Age/Sex/Location
ATM At the moment

B

B Back
BBL Be back later
BBS Be back soon
BC Because
BCNU Be Seein' You
BFD Big Freaking Deal
BFN Bye for now
BG Big grin
BICBW But I could be wrong
BMG Be my guest
BRB Be right back
BTA But then again
BTW By the way

C

CFN Ciao for now
CID Consider it done
CUL or CUL8R See you later
CYA See you (later)

D

DITTOS Diminished Intelligence Through Totalitarian  Oppression Survives (ADCO)
DOG Depend on God
DQMOT Don't quote me on this
DYOH Do your own homework
 

E

EOM End of message

F

FAQ Frequently asked questions
FROG Fully Rely On God
FWIW For what it's worth
FYI For your information
FUBAR Fouled up beyond repair (polite form)

G

GG Good game/Good going
GL Good luck
GMTA Great minds think alike
GRA Go right ahead
GW Good work

H

HT Hi there
HTH Hope this helps
HO Hold on
HOP Hold on please

I

IAC In any case
IAE In any event
IDK I don't know
IIRC If I recall correctly
IM Instant message
IMHO In my humble opinion
IMO In my opinion
IMPOV In my point of view
IMS I am sorry
IOW In other words

J

JIC Just in case
JIL Jesus is Lord
JK Just kidding
JTLYK Just to let you know

K

K Okay

KISMIF Keep It Simple, Make it Fun
KISS Keep it simple, Stupid

L

L8R Later
LOL Laughing out loud, laugh out loud

M

MDCK Maybe Dave Cowles knows!

N

NBD No big deal
NP No problem
NRN No response necessary

O

OH Off hand
OIC Oh I see
OTOH On the other hand
OTP On the phone

P

PLS Please
PLZ Please
POC Point of contact
POV Point of view, privately owned vehicle
PUSH Pray Until Something Happens

Q

R

ROTFL Rolling on the floor laughing
ROTFLMAO Rolling on the floor laughing my a** off.
RSN Real soon now
RTFM Read the frigging manual (polite form) / Read the furnished materials
RUOK? Are you okay?

S

SNAFU Situation normal, all fouled up (polite form)
SYS See you soon

T

TAFN That's all for now
TBA To be announced
TBH To be honest
THX Thanks
TIA Thanks in advance
TTFN Ta ta for now
TTYL Talk to you later
TY Thank You

U

V

VDCNN Visit Dave Cowles net now!

W

WB Welcome back
WFM Works for me
WTG Way to go
WU? What's up?

X

Y

YET You're Eligible Too!
YIM Yahoo Instant Messenger
YT? You there?
YW You're welcome

Z