A troll is someone who posts an inflamatory message hoping to generate responses from people who haven't figured out that the troll's only purpose is to stir up trouble.  The word comes from the fishing-related phrase "trolling for responses/flames," and the fact that a troll is an ugly, unfriendly creature.

When an obvious "flame-bait" thread is started, you'll also often see follow-ups that say "don't feed the trolls."

-Troy

A
AFAIK As Far as I Know
AFK Away From Keyboard
AIIC As If I Care
AISI As I See It
AKA Also Known As
ANFAWFOS And Now a Word From Our Sponsor
ASAP As Soon As Possible
ASAFP As Soon As Freakin' Possible
AYF All Your Fault
B
BAIK Boy Am I Confused
BAK Back At Keyboard
BF Boy Friend
BFN Bye For Now
BNF Big Name Fan
BNI Batteries Not Included
BOC But Of Course
BOF Birds of a Feather (Special Interest Group)
BOS Big Orange Switch (Panic Button)
BOT Back on Topic
BRB Be Right Back
BRS Big Red Switch (Panic Button)
BS Bulls*
BSEG Big S* Eating A Grin
BTDT Been There, Done That
BTFT Been There, Fixed That
BTFM Beats the Funk out of Me
BTW By the way
BUGS Bloody User Generated Symptoms
C
C&B Crash & Burn
CATCH Come Again? That Can't Help!
CE Creative Editing
CIAO Goodbye
COTFLGOHAHA Crawling on the Floor Laughing Guts Out and Having a Heart Attack
CSY Can't Stop Yawning
CU Cracking Up
CUL Catch You Later (Goodbye)
CUL8R See You Later
CWYL Chat With You Later
CYA Cover Your Ass
CYA See Ya
D
D&C Duck & Cover
DBA Doing Business As
DBN Doing Business Not
DIAFYO Did I Ask For Your Opinion
DILLIGAFF Do I look Like I give a Flying Figment?
DITUIHIBMSL Did I Tell You I Hate IBMs Lately
DITUILIBMSL Did I Tell You I Love IBMs Lately
DNPM Damn Near P*ed Myself
DUCWIC Do You See What I See?
DUCWIM Do You See What I Mean?
DUHWIH Do You Hear What I Hear?
E
E2EG Ear to Ear Grin
EOD End of Discussion
EOL End of Lecture
ESAD Eat S* And Die
ESAL Eat S* And Live
ETLA Enhanced TLA
 
F
FAQ Frequently Asked Questions
FIGMO Forget It, I've Got My Orders
FIIN F* if I Know
FITB Fill In the Blank
FM Fine Magic
FOAD F* off and Die
FOAF Friend of a Friend
FOAFOAG Father of a Friend of a Girlfriend
FOAG Father of a Girlfriend
FOT Full of Tripe
FRZ Freakin' Religious Zealot
FTASB Faster than a Speeding Bullet
FTL Faster than Light
FUA Frequently Used Acronyms
FUBAR Fouled Up (!) Beyond All Recognition (or Repair)
FUMTU F*ed up More Than Usual
FWIW For what it's worth
FYEO For Your Eyes Only
FYA For Your Action
FYI For Your Information
FYO For Your Opinion

G
GASP Go Away, Silly Person!
GD&R Grinning, Ducking and Running
GD&RVVF Grinning, Ducking and Running Very Very Fast
GF Girl Friend
GGN Gotta Go Now
GIGO Garbage In, Garbage Out
GIWIST Gee I Wish I'd Said That
GMTA Great Minds Think Alike
GOMF Get Outta My Face
GRUIT Get Reay yoU Impudent Thing
GTFOOMF Get the F* Out of My Face
H
HAND Have A Nice Day
HHO1/2K Ha Ha Only Half Kidding
HHOK Ha Ha Only Kidding
HOMPR Hang On, Mobile Phone's Ringing
HTH Hope This Helps
HWS(PEST) Husband Wants Sex (Please Excuse Slow Typing)

I
IAC In Any Case
IAE In Any Event
IANAL I Am Not A Lawyer, also IANA... such as CPA
IANALBIPOOTV I Am Not A Lawyer, But I Play One On TV
IARTPFWTSIOWIM I am Repeating this Parrot fashion without the slightest idea of what it Means
IBC Inadequate But Cute
IBM Inadequate But Marketable
ICUR I See You Are
IDGABTT It Don't Get Any Better Than This
IDGAD I Don't Give a Damn
IDGAS I Don't Give a S*
IDTS I Don't Think So
IIRC If I Remember Correctly
IITYWTMWYBMAD If I Tell You What This Means Will You Buy Me A Drink?
IITYWTMWYKM If I Tell You What This Means, Will You Kiss ME?
ILIWTPCT I Love It When the Plan Comes Together
ILSHIBAMF I Laughed so Hard I Broke All my Furniture
IMBO In My Biased Opinion
IMCO In My Considered Opinion
IMHO In My Humble Opinion
IMNSHO In My Not So Humble Opinion
IMO In My Opinion
IMVHO In My Very Humble Opinion
INPO In No Particular Order
IOW In other words
IRL In Real Life
IUD Insert Usual Disclaimers
J
JK Just Kidding
K
KISS Keep It Simple Stupid
KMA Kiss my A*
KWIM Know What I Mean?
L
L8R Later
LAGNAF Lets All Get Naked and Fool Around
LLTA Lots and Lots of Thunderous Applause
LMFAO Laughing My F* A* Off
LMTTA Leave Me the F* Alone
LOL Laughing Out Loud
LTIP Laughing Til I Puke

M
MCBTY(SN) My Computer is Better than Yours (So Nyerrr)
MFG More Friendly Garbage
MHDC(A) My Hard Drive Crashed (Again)
MMIF My Mouth Is Full
MYOB Mind Your Own Business
N
NAA! Not Another Acronym!
NBD No Big Deal
NERD National Establishment for Real Dorks
NFA No Flaming Allowed
NFW No F*ing Way
NIMBY Not in My Back Yard
NJTH Not Just Thinking Here
NOMS Not on MY System
NRN No Reply Necessary
NTL Nevertheless
NUNP No Users, No Problems
O
OATUS On a Totally Unrelated Subject
OAUS On a Related Subject
OIC Oh, I See
ONNA Oh No, Not Again
ONNTA Oh No, Not This Again
OOSOOM Out of Sight, Out of Mind
OOTC Obligatory On-Topic Comment
OTFM Only the Facts, Mam
OTC Over the Counter
OTOH On the other hand
OTTOMH Off the Top of My Head
OTTOMHAROOB Off the Top of My Head and Rolling Out of Bounds
OTW On the Whole
OWTTE Or Words to that Effect
P
PBKAC Problem Between Keyboard and Chair
PFM Pure Freaking Magic
PITA Pain In The Ass
PMETC Pardon Me, etc.
PMYMHMMFSWGAD Pardon Me, You Must Have Mistaken Me for Someone Who Gives A Damn
POQ P* Off Quickly
POQADCB P* Off Quickly and Don't Come back
POV Point of View
PPP Petty Pet Peeve
PTMM Please Tell Me More

R
ROFFNAR Rolling on the Floor for no Apparent Reason
ROFL Rolling on Floor Laughing
ROFLOL Rolling on the Floor Laughing Out Loud
ROFLMAO Rolling on Floor Laughing My Ass Off
ROFLOLBAG Rolling on the Floor Laughing Out Loud Busting a Gut
ROFPML Rolling on the Floor P*ing Myself Laughing
ROTBA Reality on the Blink Again
RSN Real Soon Now [which may be a long time coming]
RTFI Read the Friendly Instructions
RTFM Read the Freakin' manual!
RTFMA Read the Manual, Sir!
S
SAR Some Assembly Required
SBCN Sitting Behind the Computer, Naked
SHM S* Happens, Mate
SICS Sitting in Chair Snickering
SIIN S* if I Know
SNAFU Situation Normal: All Fouled (!) Up
SITD Still in the dark
SO Significant Other
SOE Silly/Stupid Operator Error
SOL Still Out of Luck (or something thereabouts )
SOP Standard Operational Procedure
T
TANJ There Aint No Justice -- Niven
TANSTAAFL There Ain't No Such Thing As A Free lunch
TCB Taking Care of Business
TDMATBICPLY This Doesn't Mean A Thing But It Confuses People Like You
TGAL Think Globally, Act Locally
TIA Thanks In Advance (also AtDhVaAnNkCsE)
TIC Tongue in cheek
TINALO This is Not a Legal Opinion
TINAR This is Not a Recommendation
TINWIS That is Not What I Said
TLA Three Letter Acronym (such as this)
TM Trust Me
TNOTVS There's Nothing on Television, so...
TPS(S) This Program Sucks, (Severely)
TPTB The Powers That Be
TRDMC Tears Running Down My Cheeks
TSOHF Total Sense of Humor Failure
TTBOMK To the Best of My Knowledge
TTFN Ta Ta for Now
TTM To The Moderator
TTYL Talk To You Later
TTYRS Talk To You Real Soon
TUFD The User File Died
V
VETLA Very Enhanced TLA
W
WAB What, Another Bill
WAMKSAM Why are My Kitties (Kids) Staring at Me
WB Welcome Back
WBS Write Back Soon
WDYMBT What do You Mean by That
WIBAMU Well, I'll be a Monkey's Uncle
WMMOWS Wash My Mouth Out with Soap
WTF What the F*?
WTG Way To Go
WTH What the H*?
WYLABOCTGWTR Would You Like a Bowl of Cream to go with That Remark?
WYLASOMWTC Would You Like a Saucer of Milk with that Comment?
WYSIAWYG What You See is Almost What You Get
WYSIWYG What You See Is What You Get
WYSINWNWYG What You See Is No Where Near What You Get
WYSINWYG What You See Is NOT What You Get
WYPIWYG What You Printed Is What You've Got
WYTYSYDG What You Thought You Saw, You Didn't Get

Y
YAOTM Yet Another Off-Topic Message
YHGASPL You Have Got A Serious Problem, Lad!
YSWUS Yea, Sure Whatever You Say!
YMMV Your Mileage may vary
YSS You Suck Severely
YWSYLS You win some, you lose some

That's one of the short lists.

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