Welcome aboard
You will find lots of new and confusing acronyms and abbreviations here, so it can be tricky to get up to speed at first.
OK, you know about U4E - Unreal4Ever, a replacement weapons pack.
PuF = Planet Unreal Forums
mod = third party add-on program for the game
RA = Rocket Arena, a 1v1 or 2v2 duelling mod
TO = Tactical Ops, a paramilitary type mod
SF = Strike Force, see above
GOTY = Game of the Year Edition, the upcoming UT re-release
pub = public server, somewhere anyone can play
LPB = low-ping bastard, a player with a fast connection
HPW = high-ping whiner, a player with a slow connection
RL = rocket launcher
SB = shield belt
DA = damage amp, (alternatively, DragonAsh)
xloc = translocator
O = Offense, attacking in CTF
D = Defense, guarding the flag in CTF
NC = Nali City, a website to download maps from
Please add some more people!