oh, blimey. Big topic.
Lol, rofl, lmao, roflmao, rolfcopter, kek = I say, how droll.
brb, gtg, bbs, bbl = Do it on your own.
LFG, LFM = Do it in a group.
DOT = damage over time
ROF/A = Rate of fire/attack
DD = Direct damage.
The list just goes on. Of course, abbreviations are one thing, sometimes there's just jargon, abbreviated or not, to get through, and it tends to be based on game.
"lol! I picked up an AM S BPC on contracts for 10k ISK, figure I could use it for my EW frig, to back up the AFs and HACs, since I need a load. The ROF on these T2 blasters in ridiculous!"
Would translate into - "Laugh out loud! I got a Small Antimatter blueprint copy on contracts for 10,000 interstellar kredits, figure I could use it for my electronic warfare frigate, to back up the assault frigates and heavy assault cruisers, since I need a load. The rate of fire on these Technology level 2 blasters in ridiculous!"
Which still won't make sense unless you've played EvE for a good while. Frankly you're best off just leaping in and admitting you're a noob.