AFK: Away from keyboard
BAK: Back at keyboard
BBL: Be back later
BBS: Be back soon
BF: Boyfriend
BRB: Be right back
BTW: By the way
BTDT: Been there, done that
CUL: See you later
DL: Download
F2F: Face to face
FAQ: Frequently asked questions(usually a document)
FWIW: For what it's worth
FYI: For Your Information
GF: Girlfriend
GMTA: Great minds think alike
IMHO: In my humble opinion
IMCO: In my considered opinion
IOHO: In our humble opinion
IOW: In other words
ISP: Internet service provider
L8R: Later
LOL: Laughing out loud
LMK: Let me know
TTYL: Talk to you later
TTFN: Ta-Ta for now
TYVM: Thank you very much