btw = by the way
IMHO = In My Humble Opinion
IRL = In Real Life
ISP = Internet Service Provider
TTYS = Talk To You Soon
During chats or during e-mails, to verify a comment of yours as deliberately a joke or is not to be taken seriously:
< g > = grin
< bg > = big grin
< vbg > = very big grin
< s > = smile
:-) = smile
< bs > = big smile
:> = big smile
< vbs > = very big smile
:-D = very big smile
=:-o = surprised
=:-O = "startled"
These come in handy as sometimes in print a comment can be too satirical and/or come across as brutally straightforward or "insulting" when there is no such intent. If like myself you're a quipster, mine own advice, IMHO, is to use these grins generously.
During chats or when replying to e-mails, you can indicate the level of humour at which you found something that has been typed by another:
lol = Laugh(ing) Out Loud
LOL = Laugh(ing) Out Loud (much harder laughing)
ROTFL = Rolling On The Floor Laughing
ROTFLMAO = Rolling On The Floor Laughing My *ss Off…
The use of ALL CAPS WHEN TYPING (both in e-mail and particularly in chat rooms), btw, is considered to be "shouting" and considered to be bad form. Avoid using all caps…