Most of these chat acronyms you're likely to find on forums, message boards, chat boards, and instant messaging. If you don't find the acronym you're looking for, you may want to try searching Google by typing in the acronym plus "stands for." So, for instance, if you wanted to know the meaning of BTW, you'd type in "BTW stands for." This simple phrasing has turned up many hard to find acronyms that are now categorized on this web site.

A3 - Anytime, Anyplace, Anywhere
A/S/L - Age, Sex, Location
B4N - (Good)Bye For Now
BCNU - Be Seeing You
BIL - Brother In-Law
BM Val - Be My Valentine
BOL - Best of Luck
BRB - Be Right Back
BTW - By the Way...
CU@ - See You At...
CUNT - Can't Understand Normal Thinking
CUL - See You Later
DD - Dear Daughter
DH - Dear Husband
DNR - Dinner
DS - Dear Son
DW - Dear Wife
EZ - Easy
F8 - Fate (as in "It's fate.")
FIL - Father In-Law
FWIW - For What It's Worth
FYI - For Your Information
GMTA - Great Minds Think Alike
HAND - Have a Nice Day
HRU - How Are You?
IAD8 - It's a Date
IM - Instant Message
IM4U - I'm for You
IMME - Instant Message Me (i.e., "Send me an instant message.")
IMHBAO - In My Humble But Accurate Opinion
IMHO - In My Humble Opinion
IMNSHO - In My Not So Humble Opinion
IRL - In Real Life
IYKWIM - If You Know What I Mean?
JK - Just Kidding
JMHO - Just My Humble Opinion
KOTC - Kiss on the Cheek
KWIM - Know What I Mean?
L8R - Later
LDR - Long Distance Relationship
LOL - Laughing Out Loud
LSKOL - Long, Slow Kiss on the Lips
LTNS - Long Time, No See
MHO - My Humble Opinion
MIL - Mother In-Law
MTE - My Thoughts Exactly
MU - Miss You
MUSM - Miss You So Much
NE1 - Anyone
NP - No Problem
OIC - Oh, I See!
OTOH - On The Other Hand
PCM - Please Call Me
PLS - Please
QT - Cutie
ROFL - Rolling on Floor, Laughing
ROFLOL - Rolling on Floor, Laughing Out Loud
RTFM - Read the "Bleeping" Manual
RUOK - Are You OK?
SAHM - Stay-At-Home Mom
SIL - Sister In-Law
SMH - Shaking My Head
TGIF - Thank God It's Friday
THNQ - Thank You
Thx - Thanks
TIA - Thanks In Advance
TIE - Take It Easy
TL;DR - Too Long; Didn't Read
TMI - Too Much Information
TTFN - Ta-Ta for Now
TTYL - Talk To You Later
TTYS - Talk To You Soon
U4E - Yours Forever
UR4ME - You Are for Me
UROK - You Are OK
XLNT - Excellent
XO - Hugs and Kisses
YGM - You Got Mail
YMMV - Your Mileage May Vary