Chat Lingo

Acronym/Lingo	Meaning
0-day	geek: (computer) vulnerability (that developers have zero day (a.k.a. no time) to fix)
1337	geek: (leet) spelling for elite (hacker or computer programmer)
2day	Today
2ff	Too Effing Fabulous, Too Effing Feisty (original)
2moro	Tomorrow
2nite	Tonight
4ever / 4eva	Forever
AFAICR	As Far As I Can Remember/Recall
AFIAK	As Far As I Know
ALAICR	As Long As I Can Remember/Recall
AQAP	As Quick(ly) As Possible
ASAP	As Soon As Possible
ATM	At The Moment
AWS	As We Speak
B4	Before
B4N / BfN	Bye For Now
b/f	Boyfriend
BBIAB	(I Will) Be Back In A Bit
BBIAM	(I Will) Be Back In A Minute
BF	Best Friend
BFF	Best Friend(s) Forever
BFFF	Best Effing Friend(s) Forever
BFK	Big Fat Kiss
BOL	Bawl Out Loud
BRB	(I Will) Be Right Back
BSOM	Beats the $&%* outta me. (as in, "I have no idea" or, "I have no clue".)
BS / B.S. / B/S	Bull#&%$ (Swear)
BTW	By The Way
Buddy	Chat Friend (on your chat client list)
cam	Webcam, Web Camera
Chillaxin'	Chilling And Relaxing
CTFD	Close The Front/Effing Door
CTFD	Calm The Eff Down
CTHD	Calm The Hell Down
CYA	See Ya! (as in insultive BYE!)
CYL	See You/Ya Later, Catch You Later (original)
CWYL	(I Will) Chat With You Later
D2E	Down-To-Earth
D/L	Down Low
DFC	Don't Effing Care (usually said by delinquents)
DIY	Do It Yourself
DL	Download (file from the internet)
DnO	Down And Out, Down n Out (original)
DoA	Dead On Arrival
DoS	geek: Denial of Service (Hacking Parlance)
DDoS	geek: Distributed Denial of Service (Hacking Parlance)
DWL	Dying With Laughter
EFF	Epic Effin' Fail'ure
EMG	Everything Must Go
f/o	@#$% Off (offensive)
FCS	For Christ's Sake
FFS	For Eff's Sake (Swear)
FTR	For The Record
FTSO	For The Sake Of
FTTB	For The Time Being
FUD	Effed Up Decision (original)
FUBAR / FOOBAR	Effed Up Beyond All Recognition/Repair (Military)
FUBR	Effed Up Beyond Recognition/Repair
FUBU	Effed Up Beyond Understanding (not the same as the clothes brand)
FWIW	For What It's Worth
FWIK	From What I Know
FYI	For Your Information/Info.
g/f	Girlfriend
GAL	Get A Life (original)
GFYS	Go Eff Yourself (offensive)
GM / g/m	Good Morning
GM?	Got Mail?, Got Milk? (offensive)
GMM?	Got My Mail?
GR8	Great
GTFO	Get The Eff Out
GTFU	Get The Eff Up
GTHO	Get The Hell Out
GTHU	Get The Hell Up
G2G / GTG	Got To Go (usually in a hurry)
H&K / HaK / HnK / H+K	Hugs And Kisses
hax / |-|/-\><	geek for hack
hax0r	geek: pertaining to hacking/hacker (These terms are usually used to circumnavigate authourities', such as the NSA, surveillance on the internet.)
ICU	I See You (usually on webcam)
IDFC	I Don't Effing Care (usually said by delinquents)
IDK	I Don't Know
IM	Instant Message/Messaging
IMB	In My Book
IMHO	In My Humble Opinion
IMO	In My Opinion
IMOT	In My Own Time
IMVHO	In My Very Humble Opinion
ISO	In Search Of
j/k	Joking, Just Kidding
JIT	Just In Time
Kewl! / Kewlies!	Cool!: Overwhelmingly expressing liking something, someone, an idea, etc.  This gesture is usually used with a particular emoticon: the one wearing the sunshades.
KIR	Keep, Keeping It Real (original)
KISS	Keep It Simple, Stupid (usually used by youngsters who are hiding something from someone, especially an adult)
KK	OK! OK! (Incessantly Reassuring)
KMT	Kiss/Kissing My Teeth
KOTC	Kiss On The Cheek
KOTL	Kiss On The Lips
KT	Kill/Killing Time, Kiss/Kissing Teeth
L8	Late
L8R	Later
Lappy	Laptop
LMAO	Laughing My Ass Off
LMBO	Laughing My Balls Off
LMN8	Eliminate
LOL	Laugh/Laughing Out Loud
LOLAK	Lots Of Love And Kisses
LTNS	Long Time No See
Mofo	Mother'effer' (As in, "I am a bad ass mofo!")
MILF	Mom/Mother I'd Like To Eff (offensive)
MMW	Mark My Words
MUNG	geek: Mash Until No Good (usually the stack)
NM	No Mentioning (It)
N00b / Noob	geek: Newbie/Novice/Inexperienced (hacker or computer user)
n/p	No Problem
OBTW	Oh, By The Way
OIC	Oh! I See!
OMDB	Over My Dead Body
OMG!	Oh My God!, Oh My Gosh!
OMFG	Oh My Effing God
OTOH	On The Other Hand
P2P	geek: Peer-To-Peer (Download), Point-To-Point (Internet Connection)
Pic	Picture or image
PM	Private Message, Private Chat
PoC	Piece Of Crap (Swear)
PoD	geek: Ping of Death (hacking parlance)
PoR	Point Of Retirement
PoS	Point Of Sale, Piece Of $&%* (Swear)
PoV	Point Of View (commonly referring to porn)
Pr0n	geek: Obfuscated spelling for porn.
PWN	Own/Compromise/Take Over (by hacking) (usually a computer system)
RBTL	Read Between The Lines
ROFL	Rolling On Floor Laughing
ROFLMAO	Rolling On Floor Laughing My Ass Off
ROFLMBO	Rolling On Floor Laughing My Balls Off
ROTFL	Rolling On The Floor Laughing
ROTFLMAO	Rolling On the Floor Laughing My Ass Off
ROTFLMBO	Rolling On The Floor Laughing My Balls Off
RTFM	Read The Fine/Effing Manual
RTM	Read The Manual
RTO	Return To Owner
Screenie	Screenshot
SFF	So Effin' Funny
Skiddie/Skid	geek: Script Kiddie
SMC / SMD	(Very Offensive)
SMH	Shake/Shaking My Head
SoB	Son of a *&$%# (Curse)
STBM / S2BM	Sucks To Be Me
STBU / STBY / S2BU / S2BY	Sucks To Be You/Ya
STFD	Shut The Front/Effing Door
STFD	Sit The Eff Down
STFU	Shut The Eff Up
STHD	Sit The Hell Down
STHU	Shut The Hell Up
STR8	Straight
SWAK	Sealed/Sent With A Kiss
SYFM	Shut Your Effing Mouth
t/y	Thank You
TANSTAAFL	There Ain't No Such Thing As A Free Lunch.  Pronounced tans toffle. More than often used by geeks or scientists, in reference to the phenomenon (in life) where (often overwhelming, or even noticeable) sacrificies have to be made in the process of implementing or bettering a task or concept.
TBH / 2BH	To Be Honest
THX	Thanks
TLC	Tender Loving Care
TMA	Too Much Alcohol
TMI	Too Much Info/Too Many Idiots
TMD	Too Much Drugs/Driving/Drinking/(Many)Drinks/...
TMOT	Taking My Own Time
TMP	Too Many People, Too Many Parties, Too Much Partying
TMS	Too Much Sex/Sun/...
TTYL	(I'll) Talk To You Later
TYL	Text You Later
TYVM	Thank You Very Much
UL	Upload (file to the internet)
UU / U-U / UnU	Up And Up
WB / w/b	Welcome Back
WIKI	geek: What I Know Is
WOC	Went Out Camping (original)
WOF	Went Out Fishing (original)
WOH	Went Out Hiking (original)
WOS	Went Out Shopping/Skiing/Smoking/... (original)
WPoC	Worthless Piece Of Crap (Swear)
WPoS	Worthless Piece Of $&%* (Swear)
WTMA	Way Too Much Alcohol
WTF	What/Where/Who/Why The $&%*
WTH	What/Where/Who/Why The Hell
WTMI	Way Too Much Info, Way Too Many Idiots
WTMD	Way Too Much Drugs/Driving/Drinking/(Many)Drinks/...
WTMP	Way Too Many People, Way Too Many Parties, Way Too Much Partying
WTMS	Way Too Much Sex/Sun/...
WYT	Wait Your Turn
WYWH	Wish/Wishing You Were Here
XO, XOXO	Hugs & Kisses
XX, XXX	Kisses
y/w	You're Welcome