Each war brings with it an alphabet soup of new, and recycled, acronyms. Below are some that are showing up in Iraq. 

AIF- anti-Iraqi forces
Angels- KIAs that die in a military hospital while undergoing care. 
AO- Area of Operations
AOR- Area of Responsibility
ASR- Alternate Supply Route
BIAP- Baghdad International Airport
CASH- combat support hospital. 
CPA- Coalition Provisional Authority
CPIC- Combined Press Information Center.
EPW- Enemy prisoner of war
FRE- Former Regime Extremists
HVT- high value target
IDP- Internally Displaced Person (like Fallujah refugees)
IED- improvised explosive device, usually a roadside bomb.
IIG-Iraqi Interim Government, which took over from CPA
ING- Iraqi National Guard
IP- Iraqi Police
KIA- killed in action.
LSA- Life Support Area
METL- Mission Essential Task List
MNF- multinational forces (coalition troops).
MSR- Mail Supply Route
ORMP- Off-Duty Risk Magnification (what personnel -- both officer and enlisted -- often indulge in when not on duty; stuff like drinking 17 beers and then trying to drive home, etc.)
PBIED- person-borne improvised explosive devices
POW-prisoner of war (American)
RCIED- Remote Controlled Improvised Explosive Device
RTD- returned to duty.
SAF- Small Arms Fire
SIDPERS- Silly Idiots Desperately Pretending Everything's Running Smoothly, or SIDetrack PERSonnel (maybe they'll go away)
SORT- Senior Officer Rest Time
TAL- Transitional Administrative Law, interim constitution, to be created by the TNA
TF- Task Force
TNA- Transitional National Assembly, to be elected this month 
VBIED- vehicle-borne improvised explosive devices
WIA- wounded in action
WMD- weapons of mass destruction