Abbreviations have been used since the inception of email.  With the popularity of cell phone text messaging, abbreviated chat usage has expanded.  Included here are only some of the major abbreviations that you may see in emails or used in online chat.  If you don't understand an abbreviation or acronym used by someone, ask what it means.

Abbreviation	Meaning
AAMOF	As a matter of fact
AFAIK	As far as I know
BBFN	Bye bye for now
BCNU	Be seeing you
BRB	Be right back
BTW	By the way
CU L8R	See you later
FWIW	For what it's worth
FYI	For your information
IAC	In any case
ICBW	I could be wrong
IMO	In my opinion
IMHO	In my humble opinion
IOW	In other words
LOL	Laugh(ing) out loud
OAS	On another subject
RL	Real life
ROTFL	Roll(ing) on the floor laughing
RT	Real time
TIA	Thanks in advance
TTFN	Ta Ta for now
TTYL	Talk to you later
TY or TYVM	Thank you or Thank you very much
WYSIWYG	What you see is what you get