Let’s try to compile as complete a list as possible of acronyms, abbreviations, etc., used on English-speaking chatrooms, blogs and message boards! Just, you know, to help newbies acclimate more quickly. I’ll start, using mostly ones I’ve encountered on the SDMB:
BTW – by the way
FYI – for your information
IANA? – I am not a (L for lawyer, D for doctor, etc.)
IMHO – in my humble opinion
IMNSHO – in my not-so-humble opinion
IMO – in my opinion
IRL – in real life (as opposed to fiction; also, as opposed to online presence – e.g., “LMIRL” – let’s meet in real life (would never have seen that one if I hadn’t caught a scary commerical warning parents about the dangers to their children of sexual predators trolling online)
LMAO – laughing my ass off
OTOH – on the other hand
ROTFLMAO – rolling on the floor laughing my ass off
SO – significant other
WTF? – what the fuck?
YMMV – your mileage may vary (i.e., you may have a different opinion or impression regarding these facts than the one I have just stated)