Abbreviations SL

A
Acc = Account
AFK = Away from my keyboard
Alt = An alternative avatar - owned by the same person but with a different name and appearance
AO = Animation Override (Makes your avatar walk and move more naturally)
ASL or A/S/L = Age Sex Location
ATM = At the moment
Avatar = The form you take in SL - can be human, alien, an animal, Vampire, etc
Awwww = Cute or lovely

B
BB = Bye Bye
Bi Bi = Bye Bye
BBL = Be back later
BBS = Be back soon
BF = Boyfriend
Booted = Unexpectedly being logged out of SL
BRB = Be right back
BS = Bull sh*t
BTW = By the way

C
CU = See you
CYA = See ya (later)
Cyber = Internet sex 

D
DK = Don't know
DND = Do Not Disturb

E
Eeeeek! = An exclamation of fear

F
FYI = For your information

G
G1 - Good one
G2G = Got to go
GF = Girlfriend
GFU = Good for you
GL = Good luck
GN = Good night
Grrrr = Anger or annoyance
Gr8 = Great
GTG = Got to go


H
HB = Hurry back
HBD = Happy birthday
HBTU = Happy birthday to you
Huh? = What or I don't understand

I
IC = I see
IDC = I don't care
IDK = I don't know
ILY or ILU = I love you
IM = Instant / private message
In world = In Second Life
IRL = In real life

J
JK = Joke or just kidding

K
KK = Okay
KAY = okay
KMP = Keep me posted
Kewl = Cool
Kinda = Kind of or sort of

L
Lag = Slow reaction time when using Second Life
LL = Linden Lab, the makers of Second Life
LOL = Laughing out loud
LMAO = Laughing my ass off
L8R = Later

M
M8 = Mate
MP = SL Marketplace
MYOB = Mind your own business

N
Nada = Nothing
Nerd = Intelligent but socially inept person 
Newb, Noob or Noobie = New avatar in SL, new comer 
NFI = No f**king idea
Nimrod = Stupid person or idiot
Nini = Night night or good night 
NOMB = None of my business
NP = No problem
NM = Never mind or no matter

O
O_O = Confused
OIC = Oh I see
OMG = Oh my God (or Goddess)
OMW = On my way

P
Peeps = People
Pffft = I don't care or it doesn't matter
PLS = please
PLZ = please
PM = Personal/Private Message
PML = Peeing myself laughing
Poofed = Disappeared, logged off or moved to another location quickly or unexpectedly
PPL = People
Prims = 3D shapes used by residents to build objects in SL

Q
Qn = Question
QQ4U = Quick question for you
QT = Cutie

R
Rezz = An item 'appearing' in-world or to make an item appear
RL = Real Life
RLY = Really
ROFL = Rolling on the floor laughing!
ROFLMAO = Rolling on the floor laughing my ass off!
ROFLOL = Roll on floor laughing out loud!
ROTFL = Rolling on the floor laughing!
RP = Role play

S
Sculptie or sculpted prim = Special prims used to create complex shapes and objects in SL. Usually created using a 3D modeling tool and then uploaded into world

SD = Sit down
Shape = The size, shape and height of an avatar's body. A shape is worn. 
Sim = Allotments of land in SL that are 65,536m square (Daydream Island is a sim) 
Skin = The exterior appearance of your avatar, excluding shape and clothes. Skins are worn. 
SL = Second Life
S'matter? = What's the matter?
SRY = Sorry
STFU = Shut the f**k up 
S'up? = What's up? 

T
Tata = Goodbye
TBH = To be honest
TC = Take care
TGIF = Thank God it's Friday
TMI = Too much information
TP = Teleport
THX = Thanks
TOS = Terms of service
TTFN = Tata for now
TTYL = Talk to you later
TTYS = Talk to you soon
TXT = Text
TY = Thank you
TYT = Take your time
TYVM = Thank you very much

U
U = You
UR = You are or your
URW = You are welcome
UVW - You're very welcome

V
V = Very
Veg or veg out  = Sit around and do nothing 
Viewer = The program used to log into SL and play in-world. There are several available.  

W
W8 = Wait
Woohoo = Horray
Woot = Expression of joy or exuberance
WTB = Want to buy
WTF = What the f**k?
WTG = Way to go!

X
X = kiss
XD = Happy or smiling
XOXO = hugs and kisses

Y
Yup or yuppers = Yes
YW = You’re welcome
YVW = You’re very welcome

Z
Zzzzz = Bored or sleepy

Other
:) = Smiling / happy
:))) = Big smiles
:( = Sad
:((( = Very sad
:D = Happy
^.^ = Happy
O.O = Wide eyed