I am a newby myself but here are a few:
FOWLR- Fish only with live rock
DSB- Deep sand bed
IMO- in my opinion
RO/DI- Reverse osmosis/ Deionized water( good water)
LFS- Local fish store
MH- Metal Halide
LS- Live sand
LR- live rock
CC- crushed coral
RR- Reef ready
RBTA- Rose bubble tip anemone
BTW- Between
HLLE-Head and lateral line erosion
These are all I can remember!!! :cheer: