Thanks MetroAir, NM, JohnK & serfty.
Have edited to add:
748 - Boeing 747-8 series aircraft (perhaps we can include other aircraft types later)
AOC: Air Operator’s Certificate (license to fly)
AQIS: Australian Quarantine and Inspection Services
DYKWIA:  Do You Know Who I Am? 
HH:  Hilton Honors - the Hilton frequent stay program
NM:  Nelly Mobbs – an infamous AFF & FT member
RTFM:  "Read The cough*ing Manual"
SACL:  Sydney Airports Corporation Limited
And to keep the list a little tidy and Australian specific, I’ve edited and deleted:
CRC: Crown Room Club - the airport lounge program for Delta AirLines
EUA: Continental and Northwest's Elite Upgrade Automation system 
EVIP: Refers to one-way, systemwide upgrades given to AA elites 
HK49s: United's confirmable North American upgrade certificates 
MLL: Maple Leaf Lounge - Air Canada's network of airport lounges 
PC: Presidents Club - Continental's network of airport lounges
RC: Regency Club, a.k.a. Hyatt club lounge
RCC: United's Red Carpet Club 
VIPOW: One-way complimentary system-wide upgrade certificate on AA.