Here are a few that I know.
DD - Darling Daughter
DS - Darling Son
DH - Darling Husband
DW - Darling Wife
DSS - Darling Step Son
DSD - Darling Step Daughter
MIL - Mother in law
FIL - Father in law
MNSSHP - Mickeys not so scary halloween party
MVMCP - Mickeys very merry christmas party
Poly - Pollynesian Villiage
TT - Test Track
MS - Mission Space
EE - Expeditioin Everest
YOMD - Year of a million dreams
CM - Cast Member
CR - Contemporary Resort
FW - Fort Wilderness
WL - Wilderness Lodge
MK - Magic Kingdom
AK - Animal Kingdom
AKL - Animal Kindgom Lodge
CBR - Carribian Beach Resort
CSR - Coronado Springs Resort
LOL - Lots of laughs or laughing out loud
ROTFLOL - Rolling on the floor laughing out loud
CP - Candlelight processsional
BTMRR - Big Thunder Mountain Rail Road
HM - Haunted Mansion
POTC - Pirates of the carribean
JC - Jungle Cruise
ITTBAB - It's tough to be a bug
HISTA - Honey I shrunk the audience
I know there are a ton more, but these just came to mind, spelling may be off, and these are my takes on them. Hope this helps