Acronym  Expansion 
AA Alcoholics Anonymous
AAA Travel club
AAAAA Travel club for alcoholics
ADN Any Day Now
AFAIK As Far As I Know
AFK Away From the Keyboard
AKA Also known as
AWGTHTGTTA Are We Going To Have To Go Through This Again
B4N Bye for Now
BAD Broken as Designed
BAMF Bad Assed Motherfucker
BBL Be Back Later
BBR Burnt Beyond Repair
BBS Bulletin Board System
BFD Big Fuckin' Deal
BIOYIOP Blow It Out Your I/O Port
BISD Built-in shit detector
BITGOD Back in the good old days
BOFH Bastard operator from hell (UNIX), from http://bofh.ntk.net/Bastard.html
BOHICA Bend Over, Here It Comes Again (military for getting screwed)
BRB Be Right Back
BRS Big Red Switch
BSOD Blue screen of death (PMS Microsoft style)
BTA But Then Again (in response to IOW)
BTW By The Way
BYAM Between you and me
BWQ Buzz Word Quotient
CI$ Compu$erve Information Service
CTS Consider the source
CU See you
CUL See you Later
CUL8R See you Later
DIIK Damned If I Know
DILLIGAF Does It Look Like I Give A Fuck
DIY Do it yourself
DL or D/L Download, transmit to you
DTP DeskTop Publishing
DTRT Do The Right Thing
DWIMC Do What I Mean, Correctly
EAPG Early American Pressed Glass
EOT End Of Thread (ie. don't reply to this message)
ES&D Eat Shit and Die
ESABATM Eat Shit And Bark at the Moon
ETLA Extended Three Letter Acronym
FFRD Flying Fuck in a Rolling Donut (I don't give one)
FHOF Freeware Hall of Fame
FISH First In, Still Here
FITB Fill In The Blank
FLMN Four letter mnemonic name (cf. TLA)
FOAF Friend of A Friend
FOB Fresh off the Boat
FOMCL Fell off my chair laughing
FOOBAR Variant of FUBAR (q.v.)
FOOMCL Fell out of my chair laughing
FOS Freedom Of Speech; Full Of Shit
FRED Fucking Ridiculous Electronic Device
FTM, RTFC Forget the manual, read the fucking code
FTTT From Time To Time
FUBAR Fucked Up Beyond All Repair
FTW Fuck the World
FUD Fear, Uncertainty and Doubt
FURTB Full up ready to burst (about hard disk drives)
FWIW For What It's Worth
FY&TSYRIO Fuck You And The Sysop You Rode In On
FYA&E For your amusement and edification
FYDITM Fuck You Directly In The Mouth
FYI For Your Information
g Grin
GAFIA Get Away From It All
gd&r grinning, ducking and running
gd&arf grinning, ducking and running FAST!
gd&arvvf grinning, ducking and running VERY VERY FAST!
gd&aw grinning, ducking and weaving
GFR Grim File Reaper (pervasive data destroyer)
GFY Good for you, or Go f*** yourself, depending on context
GH Getting Hard
GIGO Garbage In, Garbage Out
GIWIST Gee, I Wish I'd Said That
GLGH Good Luck and Good Hunting
GMTA Great Minds Think Alike
GW Getting Wet
HIIK Hell if I Know
HMOFG or HMFG Holy Mother Of Fucking God.
HTH Hope this helps
IAC In Any Case
IAE In Any Event
IANAL/A/D/B I am not a lawyer/attorney/doctor, but
IC I See
IDTT I'll Drink To That
IIRC If I recall correctly
IITYWIMIWHTKY If I tell you what it means, I will have to kill you
IITYWIMWYBMAD If I tell you what it means, will you buy me a drink
ILTNMMAMOTC. HYCFAPMSFTJ I'd like to nominate Mike Meyer as moderator of that conference. Honestly you couldn't find a person more suited for the job.
ILY I Love You
IMAO In My Arrogant Opinion
IMCO In my considered opinion
IMHO In My Humble Opinion
IMNSHO In My Not So Humble Opinion
IMO In My Opinion
IMOBO In My Own Biased Opinion.
INPO In No Particular Order
IOW In Other Words
IWBNI It Would Be Nice If
IYFEG Insert Your Favorite Ethnic Group
JIC Just In Case
JSNM Just Stark Naked Magic
JTYWTK Just Thought You Wanted To Know
KMYF Kiss Me You Fool
L8R Later
LAB&TYD Life's A Bitch & Then You Die.
LLTA; LALOTA Lots and Lots of Thunderous Applause
LMAO Laughing My Ass Off
LMWIS Lick Me Where I Sweat
LOL Laughing Out Loud (originally - now in chat groups the equivalent of a teenager's overused and meaningless "y'know")
MLA Multiple Letter Acronym
MOTAS Member of the Appropriate Sex
MOTOS Member of the Opposite Sex
MOTSS Member of the Same Sex
NFW No Fucking Way
NIMBY Not in my backyard
NIXON When you can't say shit, ie "Take a Nixon"
NSS No Shit, Sherlock
ObTWIAVBP Obligatory the world is a very big place (what's obvious locally may puzzle outsiders)
OIC Oh, I See
ONLY Used by shareware authors who over-price, ie. "Only $99.95."
OOTC Obligatory On Topic Comment
OTF On the Floor
OTOH On The Other Hand
OTTH On the third hand
PABG Pack a Big Gun
PCYLIHOONL Please Cross Your Legs, I Have Only One Nail Left
PITA Pain In The Ass (origin of pitabytes, coined here to mean spam and Internet advertising)
PLOKTA Press Lots Of Keys To Abort
PMBI Pardon my butting in
PMFBI Pardon Me For Butting In
POSSLQ Person of Opposite Sex Sharing Living Quarters
POV Point Of View
PTB Powers that be
RE Regarding
ROTFL Rolling On The Floor Laughing
ROTFLMAO Rolling on the floor laughing my ass off
ROTFLAHMS Rolling On The Floor Laughing And Holding My Side
RPG Role Playing Games
RSN Real Soon Now
RTFM Read The Fucking Manual
SFLA Stupid Four Letter Acronym
SIG Special Interest Group
SIAANMHOOEI Stupidity is always astounding no matter how often one encounters it
SMO; SMON Serious Mode On
SMOP Small Matter of Programming
SMOff Serious Mode Off
SNAFU Situation Normal - All Fucked Up
SO Significant Other
SOB Son of a bitch
SPAM Junk email (from SPiced hAM, Hormel's junk meat)
ST-TNG Star Trek, The Next Generation
ST-TOS Star Trek, The Original Series
STI/ST-TMP Star Trek, The Motion Picture
STII/ST-WOK Star Trek, Wrath of Khan
STIII/ST-SFS Star Trek, Search for Spock
STIV/ST-TVH Star Trek, The Voyage Home
STV/ST-TFF Star Trek, The Final Frontier
STVI/ST-TUC Star Trek, The Undiscovered Country
SWMBO She Who Must Be Obeyed
SYSOP SYStem OPerator, aka God
TAFN That's All For Now
TAFT That's a frightening thought
TANJ There Ain't No Justice
TANSTAAFL There Ain't No Such Thing As A Free Lunch
TNSTAAFL There's No Such Thing As A Free Lunch
TDLS(CNMSBNOWT) The dirty little secret (Conservatives need more sex but no one wants them)
TDM Too Damn Many
TGIF Thank God Its Friday
TIA Thanks In Advance
TIATLG Truly, I Am The Living God
TLA Three Letter Acronym
TLG The Living God (unless otherwise applied it refers to Jim Lee of Los Angeles)
TPTB The Powers That Be
TSJD Texas Size Jelly Donut - official food of Texas sysops
TSR Terminate and Stay Resident program
TTBOMK To The Best Of My Knowledge
TTFN Ta-Ta For Now
TTL4N That's The Lot For Now
TTUL Talk (or Type) To You Later
UAE Unrecoverable application error (Bane of Windows users)
UL or U/L Upload, send to the BBS
WATMHATTAH Why are there more horses asses than there are horses
WFM Works For Me
WIMP Windows, Icons, Mouse, Pointing
WOFTAM Waste Of Fucking Time And Money
WRT With Regard To
WTF What the Fuck
WTFDIK What the Fuck Do I Know
WTMTOYH Way too much time on your hands
WYGIWYPF What You Get Is What You Pay For
WYITF Wrapping yourself in the flag (Like KY Jelly adopting the slogan: "In order to form a more perfect union?")
WYSIWYG What You See Is What You Get
YABA Yet Another Bloody Acronym
YMMV Your Mileage May Vary.
<arching eyebrows> *blush* <chuckle>
<falling off the soapbox> <frown> <grin>
*hug* *kiss* <lewd wink>
<making notes...> <mounting the soapbox> <raising eyebrows>
<sheepish grin> <Sheesh!>(tm) <silly grin>
<smile> <smiling sweetly> <smirk>
<wink> <nudge nudge, wink wink>  
Emoticon Meaning
:) :-) :> Smiling, happy faces; don't take me too seriously
;) ;-) ;> Winking happy faces (something said tongue-in-cheek)
B-) Smiling face from a person wearing glasses
8-) Smiling face with a wide-eyed look
:D :-D Wider happy face (or Mistrel singers)
:-o "Oh, nooooooo!" (a la Mr. Bill)
:-( Sad or disappointed face
:-P Tongue stuck out
:-J Tongue in cheek
:-# Message concerning something that shouldn't have been said...
:-$ Message indicating person is ill...
:-& Message indicating person is angry...
:-* Kiss...
:-x Kiss kiss
:-(=) Message from a person with big teeth.
<:-) Dumb questions
<g> Grin
|-( Late night messages
:^) From a person with a large nose
:*) Clowning around
:-{#} From a person with braces
&:-) From a person with curly hair
@:-) From a person with wavy hair
#:-) From a person with matted hair
O:-) Angel
C=:-) Chef
;-)}<////> Corporate-type guy (see the necktie?)
:-) )-: Masking theatrical comments
:-|K- Formal message.
<:>== A turkey
...---... S.O.S.
O:O A girl is mooning you
@*&$!% You know what that means...
2B|^2B Message about Shakespeare
(O--< A fishy message...
@>--->---- A rose.
(-_-) Secret smile
(.)(.) Ms. Dos