This should cover everything. From my forums FAQ Introduction page.
Common Forum/Computer Abbreviations:A24/7 - 24 hours a day, 7 days a week
AAMOF - As A Matter Of Fact
AFAIK - As Far As I Know
AFK - Away From Keyboard
AKA - Also Known As
ANY1 - Anyone
ASAP - As Soon As Possible
ASL - Age/ Sex/ Location?
ATB - All The Best
ATTN - Attention
BB1G1 or BOGO - Buy One Get One Free
BB - Best Buy
BBL - Be Back Later
BBIAB - Be Back In A Bit
BION - Believe It Or Not
BOL - Best Of Luck
BRB - Be Right Back
BTW - By The Way
CCYA - See ya
CYM - Check Your Mail
CU - See you
DDIM - Do It Myself
DIY - Do It Yourself
DK - Don't Know
DOB - Date Of Birth
FFAQ - Frequently Asked Question(s)
FWIW - For What It's Worth
FYI - For Your Information
GGC - Gift Certificate
GDA - Good Deal At
GMTA - Great Minds Think Alike
GR8 - Great
GTG - Got To Go
HHAND - Have A Nice Day
HTH - Hope This Helps
IIME - In My Experience
IIRC - If I Recall Correctly
IMAO - In My Arrogant Opinion
IMHO - In My Honest/Humble Opinion
IMO - In My Opinion
IOU - I Owe You
IRL - In Real Life
ISO - In Search Of (Info, parts etc)
JJK - Just Kidding
J/K - Just Kidding (or Joke)
JMHO - Just My Humble Opinion
JMO - Just My Opinion
JSYK - Just So You Know
LLOL - Laughing Out Loud
LMAO - Laughing My Arse Off
LMK - Let Me Know
LTNS - Long Time No See
NNBD - No Big Deal
NE1 - Anyone
NOYB - None Of Your Business
OOEM - Original Equipment Manufacturer
OIC - Oh I See
OOS - Out Of Stock
OT - Off Topic
OTOH - On The Other Hand
OW - Oh Well
PPM - Private Message
PTMM - Please Tell Me More
PTMY - Pleased To Meet You
RRAOK - Random Act Of Kindness
RE - Regarding
ROFL - Rolling On (the) Floor Laughing
ROFLMAO - Rolling On The Floor Laughing My Arse Off
ROTM - Right On The Money
S SAR - Smart Arse Remark
SCNR - Sorry, Could Not Resist
SETE - Smiling Ear To Ear
S/H - Shipping and Handling
SOL - nuts Out (of) Luck
STS - So To Speak
TTIA - Thanks In Advance
TMI - Too Much Information
TTOP - To The Original Poster (author of thread)
TTYL - Talk To You Later
TYVM - Thank You Very Much
WWIW - What's It Worth
WTB - Where to buy
WTF - What the F#%k
WTF - Where the F#%k
Y YGM - You've got mail
YGPM - You've got (a) private message