This is a brief list of those often irritating encoded phrases that appear so much on the newsgroups and so on.
It was written by Sammy Penny (SammyTheSnake), a Physics & Computer Science student at the University of Warwick between 1997 and 2000, and subsequently maintained by Simon Heywood.
AFAIAA As Far As I Am Aware
AFAICR As Far As I Can Remember / Recall
AFAICS As Far As I Can See
AFAIK As Far As I know
AFK Away From Keyboard (an IRC-only one this)
AICBW Although I Could Be Wrong
AICM5P And I Claim My 5 Pounds, as in 'You are Clinton, AICM5P'
AIHAIG As It Happens / As It Goes
AIMHOOC All IMHO, Of Course
AISI As I See It
AIUI As I Understand It
AWA Apologies Where Appropriate
AWATCOTH And What Are The Chances Of That Happening
BIM Bourne In Mind
BRB Be Right Back [IRC-specific again]
BTDT Been There, Done That
BTIM Bear That In Mind
BTW By The Way
CYA See you
DETLA Doubly Extended TLA
ETLA Extended TLA
FFS For Fuck's Sake
FMI For My Information
FOMC Falling Off My Chair [laughing a lot]
FOTC Falling Off The Chair
FUBAR Fucked Up Beyond All Recognition
[C programmers may recognise how this has slipped
into common usage as in for(foo;bar;foobar++); ]
FUD Fear, Uncertainty and Doubt
FWIW For What It's Worth
FYI For Your Information
GIT Get In Touch
GOFAI Good Old Fasioned Artificial Intelligence
GPL (GNU) General Public License
HAND Have A Nice Day
HIR Hope / Hoping / Hopefully I'm Right
HM Hairy Muff == Fairy Nuff == fair enough
HTH Hope / Hoping / Hopefully) This Helps
IANAL I Am Not A Lawyer
IBTIM I'll Bear That In Mind
ICBW I Could Be Wrong
IIGC If I Guess Correctly
IIRC If I Remember Correctly
IIRCWIMN IIRC, Which I Might Not
IIRCWIPD IIRC, Which I Probably Don't
IKWYM I Know What You Mean
IME In My Experience
IMNSHO In My Not So Humble Opinion
IMHO In My Humble Opinion
IMO In My Opinion
IMS If Memory Serves
IRC Internet Relay Chat
ISTR I Seem To Remeber
ITYWFI I'll Take Your Word For It
IWITOIF I Wish I'd Thought Of It First
IYSWIM If You See What I Mean
IYKWIM(AITYD) If You Know What I Mean (And I Think You Do)
JAT Just A Thought
JFW Just Fucking Works
[i.e. you don't have to spend hours reading
manuals and trawling through mailing list archives]
JMTCW Just My Two Cent's Worth
JMTPW Just My Two Pence's Worth
JFMI Just For My Information
JOOI Just Out Of Interest
KIT Keep In Touch
LMAO Laughing My Arse Off
LOL Laughing Out Loud
LOVL Laughing Out Very Loud
NIFO(T)C Naked In Front Of (The) Computer
NSFW Not Safe For Work
NTIKO Not / None That I Know Of
OCICBW Of Course I Could Be Wrong
OIC Oh, I See
OSIS Or So It Seems
OWTTA Or Words To That Affect
PITA Pain In The Arse [or 'Ass' if you're stupid]
POV Point Of View or Persistence Of Vision
RE REturned [seen on IRC]
ROTFL(MAO) Rolling On The Floor Laughing (My Arse Off)
ROTFLABTC " " " " " And Biting The Carpet [a zarqism]
RTFM Read The Fucking Manual
RTFJF RTF Jargon File [try http://catb.org/~esr/jargon/]
SICCO Simple Informative Consise Complete On-topic [another zarqism]
SNAFU Situation Normal, All Fucked Up
SNR Signal to Noise Ratio
SMPOV See My POV?
SOTO Statement Of The Obvious
STDS Software That Doesn't Suck [e.g. Linux ;-)]
SWIM See What I Mean?
TANSTAAFL There Ain't No Such Thing As A Free Lunch [yet another zarqism]
TATWAPOS Take All This With A Pinch Of Salt
TIFM This Is From Memory
TFL Thanks For Listening
TFYA Thanks For Your Attention
TIA Thanks In Advance
TLA Three Letter Abbreviation / Acronym
TMTOWTDI There's More Than One Way To Do It [Perl motto]
TSOGL Thirty Seconds On Google Later
TTBOMK To The Best Of My Knowledge
TTFN Ta Ta For Now
TTOTD Top Tip Of The Day [Cheers, Jaffa]
TTWAPOS Take This With A Pinch Of Salt
TVM Thanks / Ta Very Much
TVMIA TVM In Advance
WB Welcome Back
WRT With Respect To
WTF What The Fuck
YAGPLFW Yet Another GPL Flame War
YHBT You Have Been Trolled
YHL You Have Lost
YKWIM You Know What I Mean
YMMV Your Mileage May Vary [your level of success can't be predicted]
YWYTOIF You Wish You'd Thought Of It First