| A |
| A&AFES | Army and Air Force Exchange Service |
| A&DSL | Administrative and Direct Support Logistics |
| A/C | Aircraft |
| AA | Air-to-Air weapon |
| AA | Antiaircraft |
| AAA | Air Assault Ambush Flight Operation |
| AAA | Antiaircraft Artillery |
| AAC | Autonomous Administrative Committee |
| AACT | Aerial Aviation Control Team |
| AAD | ARVN Associated Depot |
| AAD-LB | ARVN Associated Depot Long Binh |
| AAE | Army Aviation Element |
| AAEOI | Associated American Engineers Overseas, Incorporated |
| AAF | Army Airfield |
| AAFES | Army and Air Force Exchange System |
| AAFPS | Army Air Force Postal Service |
| AAFRES | Air Force Regional Exchange System |
| AAG | Army Advisory Group |
| AAM | Air-to-Air missile |
| AAOS | Army Aviation Operations Section |
| AAS | Automatic Addressing System |
| AATT | Australian Army Training Team |
| AATTV | Australian Army Training Team, Vietnam |
| AAVSCOM | Army Aviation Support Command (United States) |
| AAWC | Anti-Air-Warfare Commander |
| AB | Afterburner |
| AB | Air Base |
| AB&T | Alaska Barge & Transport, Inc. |
| ABC | Airborne Communication |
| ABC | American Broadcasting Company |
| ABCC | Airborne Communications Center |
| ABCCC | Airborne Battlefield Command and Control Center |
| ABD | Accumulated Bomb Damage |
| ABF | Attack-by-Fire |
| Abn/ABN | Airborne |
| ABT | Alaska Barge & Transport |
| AC&W | Aircraft Control and Warning |
| ACA | Aircraft Clearance Authority |
| ACAD | Academy |
| ACAT | Armored Cavalry Assault Troop |
| ACAV | Armored Cavalry Assault Vehicle |
| ACC | Army Calibration Center |
| ACC | Army Component Command (er) |
| ACE | Architectural and Engineering |
| ACFT | Aircraft |
| ACI | Airborne Communication Intercept |
| ACM | Air Chief Marshal |
| ACM | Air Combat Maneuvering |
| ACM | Army Commendation Medal |
| ACO | Administrative Contracting Officer |
| ACofS/ACOS | Assistant Chief of Staff |
| ACR | Armored Cavalry Regiment |
| ACS | Air Commando Squadron |
| ACS | Armored Cavalry Squadron |
| ACSFOR | Assistant Chief of Staff for Force Development |
| ACT | Air Combat Tactics |
| ACTIV | Army Concept Team in Vietnam |
| ACTOV | Accelerated Turnover to Vietnamese |
| ACTOVCARD | Accelerated Turnover to Vietnamese Automated Records |
| ACTOVCOMM | Accelerated Turnover to Vietnamese Communications |
| ACTOVINT | Accelerated Turnover to Vietnamese Intelligence |
| ACTOVLOG | Accelerated Turnover to Vietnamese Logistics |
| ACTOVMED/DENT | Accelerated Turnover to Vietnamese Medical/Dental |
| ACTOVOPS | Accelerated Turnover to Vietnamese Operations |
| ACTOVPLAN | Accelerated Turnover to Vietnamese Plan |
| ACTOVPOW | Accelerated Turnover to Vietnamese Prisoners of War |
| ACTOVRAD | Accelerated Turnover to Vietnamese Radar |
| ACW | Air Commando Wing |
| ACY | Armed Combat Youth |
| AD | Air Defense |
| AD | Air Division |
| AD(2) | 2d Air Division |
| ADA | Air Defense Artillery |
| ADB | Agriculture Development Bank |
| ADF | Automatic Direction Finder |
| ADIZ | Air Defense Identification Zone |
| ADLMS | Aerial Delivered Land Mines System |
| ADM | Administration |
| ADM | Ap Doi Moi (New Real Life Hamlet) |
| ADMIN | Administration |
| ADMIN & FIN | Administration and Finance |
| ADP | Automatic Data Processing |
| ADPE | Automatic Data Processing Equipment |
| ADPS | Automatic Data Processing System |
| ADSID | Air Deliverable Seismic Intrusion Detectors |
| ADSRS | Automatic Document Storage and Retrieval System |
| ADTAT | Air Defense Technical Assistance Team |
| ADVON | Advanced Echelon |
| AE | Advisory Element |
| AESF | Amphibious Evacuation Security Force |
| AEW | Airborne Early Warning |
| AF | Air Force |
| AFAG | Air Force Advisory Group |
| AFAK | Armed Forces Assistance to Korea |
| AFAT | Air Force Advisory Team |
| AFB | Air Force Base |
| AFC | Air Force Cross |
| AFC | Armed Forces Council |
| AFC | Automatic Frequency Control |
| AFCC | Air Force Component Command (er) |
| AFCCC | Air Force Command and Control Center |
| AFCM | Air Force Commendation Medal |
| AFD | Armed Forces Directory |
| AFDL | Auxiliary Floating Dry Dock |
| AFES | Air Force Evaluation System (SEER) |
| AFGP | Air Force Advisory Group |
| AFGP/DO | Air Force Advisory Group Directorate of Operations |
| AFLC | Air Force Logistics Command (United States) |
| AFLD | Airfield |
| AFLS | Armed Forces Language School |
| AFLST | Armed Forces Language Screening Test |
| AFM | Air Force Manual |
| AFP | Annual Funding Program |
| AFP | Armed Forces of the Philippine |
| AFPCS | Air Force Postal and Courier Service |
| AFRS | Armed Forces Radio Service |
| AFRTS | American Forces Radio and Television Service |
| AFRTS | Armed Forces Radio and Television Service |
| AFSC | Air Force Specialty Code |
| AFSC | Air Force Systems Command |
| AFTF | Air Force Task Force |
| AFTU-V | Air Force Test Unit, Vietnam |
| AFV | Australian Force, Vietnam |
| AFVN | Air Force Vietnam |
| AFVN | American Forces Vietnam Network |
| AG | Adjutant General |
| AGE | Aerospace Ground Equipment |
| AGIL | Airborne General Illumination Light Set |
| AGL | Above Ground Level |
| AGM | Air to Ground Missile |
| AGP | Motor Torpedo Boat Tender (Auxiliary General Purpose) |
| AHB | Assault Helicopter Battalion |
| AHC | Assault Helicopter Company |
| AI | Assistant Instructor |
| AI Radar | Airborne Intercept Radar |
| AID | Agency for International Development (See USAID) |
| AIG | Address Indicator Group |
| AIK | Aide- in- Kind |
| AIK | Assistance-in-Kind |
| AIM | Air Intercept Missile |
| AIM-7 (D&E models) (SPARROW) | Semiactive radar type, air-to-air missile. |
| AIM-9 (B&D models) (SIDEWINDER) | Passive IR type, air-to-air missile. |
| AIM-9C (SIDEWINDER) | Radar guided air-to-air missile. |
| AIMI | Army Intensified Management Item |
| AIMI | Army Intensified Management Item |
| AIMI | Aviation Intensely Managed Item(s) |
| AIRA | Air Attache |
| Aircraft commander | Designated pilot-in-command of a given aircraft (Air Force name for front seater in F-4). |
| AIRDEVRON EIGHT WPD | Air Development Squadron Eight, Western Pacific Detachment |
| AIT | Advanced Individual Training |
| AK | Automatic Rifle (Soviet or CHICOM) |
| AKL | Auxiliary Cargo Lighter/Auxiliary Light Cargo Ship |
| ALC | Area/Air/Army Logistics Command |
| ALCC | Airlift Control Center |
| ALKALI | Soviet air-to-air missile - radar beam rider type. |
| Alliance | The Alliance of National and Democratic Peace forces of Viet-Nam. A front organization designed to unite communist and non-communist forces in the political struggle in South Vietnam. Specifically appealed to intellectuals in urban areas. |
| ALO | Air Liaison Officer |
| ALQ-51 | Broadband deception ECM system. |
| ALQ-71 | Noise jamming ECM pod (production model of QRC-160-1). |
| ALUSNA | American Legation United States Naval Attache |
| AM | Air Medal |
| AM | Airmobile |
| AM | Aluminum Matting |
| AM | Ambassador |
| AM | Amplitude Modulated |
| AMA | Air Materiel Area |
| AMAMB | American Ambassador |
| AMB | Ambassador |
| Ambl | Airmobile |
| AMC | Air/Army Materiel Command |
| AMC/PAC | Army Material Command/Pacific Area Command |
| AMCONGEN | American Counsul General |
| AMCONSUL | American Consulate |
| Amemb/AMEMB | American Embassy |
| AMFES | Army and Marine Forces Evaluation System (SEER) |
| AMM | Airman's Medal |
| AMMC | Aviation Materiel Management Center |
| AMMI | Navy Pontoon Barge |
| Ammo/AMMO | Ammunition |
| AMPHIB | Amphibious |
| AMS | Army Map Service |
| AMSF-V | Area Maintenance Supply Facility-Vietnam |
| AMT | Aerial Mail Terminals |
| AMTRAC | Amphibious Tractor |
| AN/APA-157 | CW radar illuminator and fire control computer for SPARROW missile system. |
| ANCHOR (Various colors - GREEN, ORANGE, RED, WHITE, BROWN) | Code names for specific aerial refueling tracks |
| ANDPF | Alliance for National Democratic and Peace Forces |
| Angle-off | Angular position off the tail of the reference aircraft. |
| ANGLICO | Air & Naval Gunfire Liaison Company |
| ANL | Net Laying Ship |
| ANZAC | Australian and New Zealand Army Corps |
| ANZUS | Australia, New Zealand and the United States |
| AO | Area of Operation(s) |
| AOA | Amphibious Objective Area |
| AOB | Air Order of Battle |
| AOC | Air Operations Center |
| AOC | Army Operations Center |
| AOSAF | DAO Air Force Division |
| AOSAF-E | DAO Air Force Division Civil Engineering Branch |
| AOSND-L | Navy Division Logistics |
| AOSOP-OT | DAO Operations & Plans Division Training Management Branch |
| AP | Antipersonnel |
| AP | Armed Propaganda |
| AP | Associated Press |
| APA | Advance Political Action |
| APA | Amphibious Assault Transport Ship |
| APA | Assistant Province Advisor |
| APACL | Asian Peoples Anti-Communist League |
| APB | Barrack Ship (Self-Propelled) |
| APC | Accelerated Pacification Campaign |
| APC | Aerial Photo Center |
| APC | Armored Personnel Carrier |
| APD | Airborne Personnel Detector |
| API | Armor Piercing-Incendiary |
| APL | Auxiliary Personnel Lighter |
| APL | Barracks Barge |
| APO | Army Post Office |
| APOE | Aerial Port of Embarkation |
| APOG | Aerial Port Group |
| APPROX | Approximately |
| APQ-100/109 | Airborne intercept radar in F-4C/D aircraft. |
| APQ-72 | Airborne intercept radar in F-4B aircraft. |
| APQ-94 | Airborne intercept radar in F-8E aircraft. |
| APR-25 | Vector homing and warning system - providing 360 degree directional warning of threat signals in certain bands with instantaneous bearing to radiating source. |
| APR-26 | Crystal video airborne warning receiver to detect SA-2 guidance signals. |
| APR-27 | Airborne radar warning receiver. |
| APS | Aerial Port Squadron |
| APT | Armed Propaganda Team |
| APT | Armor Piercing Tracer |
| AQ/4 | Drone Aircraft |
| AR | Accommodation Rate |
| AR | Army Regulation |
| ARA | Aerial Rocket Artillery |
| ARAAV | Armored Reconnaissance Airborne Assault Vehicle |
| ARC | American Red Cross |
| ARC LAPES | Single Parachute Low Altitude Extraction System |
| ARC LIGHT | B-52 Strategic Bomber Strike |
| ARCOM | Army Commendation Medal |
| ARCOV | US Army Combat Operations in Vietnam (Study Group) |
| ARDEMs | Analysis of Revolutionary Development Evaluation and Measurement System |
| ARDF | Airborne Radiation Detection and Fixing |
| ARDF | Airborne Radio Direction Finding |
| ARG | Amphibious Ready Group |
| ARG/SLF | Amphibious Ready Group/Special Landing Force |
| ARL | Auxiliary Landing Craft Repair |
| ARL | Repair Ship |
| ARMA | Army Attache |
| ARMCOM | Armament Command |
| Armd/ARMD | Armored |
| Armed Reconnaissance | Air mission flown with the primary purpose of locating and attacking targets of opportunity. |
| ARMOROCCO | Artillery/Mortar/Racket Countermeasures |
| ARP | Aero-Rifle Platoon |
| ARPA | Advanced Research Projects Agency (OSD) |
| ARPA-RDFU-V | Advanced Research Project Agency, Research and Development Field Unit, Vietnam |
| ARRG | Aerospace Rescue and Recovery Group |
| ARRGP | Aerospace Rescue Recovery Group |
| ARRS | Aerospace Rescue and Recovery Service |
| Arty/ARTY | Artillery |
| ARVN | Army of the Republic of Vietnam |
| AS | Aviation Support |
| ASA | Assistant Secretary of the Army |
| ASB | Advanced Support Base |
| ASB | Amphibious Support Battalion |
| ASC | Army Supply Center |
| ASC | Automatic Switching Center |
| ASD (Comptroller) | Assistant Secretary of Defense (Comptroller) |
| ASD (I&L) | Assistant Secretary of Defense (Installation and Logistics) |
| ASD (PA) | Assistant Secretary of Defense (Public Affairs) |
| ASD/PA | Assistant Secretary of Defense/Public Affairs |
| ASE circle | Allowable Steering Error - circle on radar display provided by fire control computer. |
| ASGN/ASGD | Assign/Assigned |
| ASHC | Assault Support Helicopter Company |
| ASID | Air-Deliverable Seismic Intrusion Detector |
| ASL | Authorised Stock List or Stockage Lists |
| ASLT | Assault |
| ASOC | Air Support Operations Center |
| ASP | Ammunition Supply Point |
| ASPB | Advanced Support Patrol Boat |
| ASPB | Armored Support Patrol Boat |
| ASPB | Assault Support Patrol Boat |
| ASPR | Armed Services Procurement Regulations |
| ASR | Ammunition Supply Rate |
| ASR | Available Supply Rate |
| ASRT | Air Support Radar Team |
| ASST | Assistant(s) |
| ASTA | Aerial Survey and Target Acquisition |
| ASTD | Army Strategic Technical Detachment |
| ASW | Antisubmarine Warfare |
| AT | Antitank |
| ATC | Air Training Command/Center |
| ATC | Armored Troop Carrier |
| ATCK | Attack |
| ATCO | Air Traffic Coordinating Office |
| ATCO | Air Transport Coordinating Office |
| ATF | Amphibious Task Force |
| ATF | Australian Task Force |
| ATG | Amphibious Task Group |
| ATK | Attack |
| ATLC | Air Technical Logistics Command |
| ATOLL | Soviet air-to-air missile, infrared seeker type |
| ATP | Army Training Program |
| ATSB | Advanced Tactical Support Base |
| ATT | Army Training Test |
| Attitude | A learned tendency to behave positively or negatively toward persons and situations. |
| AUS | Australian |
| AUTODIN | Automatic Digital Data Network |
| AUTODIN | Automatic Digital Network |
| AUTOSEVCOM | Automatic Secure Voice Communications |
| AUTOSEVOCOM | Automatic Secure Voice Communications |
| Autotrack | Automatic tracking in which a servo mechanism keeps the radar beam trained on the target. |
| AUTOVON | Automatic Voice Network |
| AVAL | Available |
| AVGAS | Aviation Gasoline |
| AVLB | Armored Vehicle Launch Bridge |
| Avn | Aviation |
| AVNK | Aviation Nationale Khmer (Cambodian Air Force) |
| AW | Automatic Weapon(s) |
| AWC | Aerial Weapons Company |
| AWOL | Absent Without Leave |
| AWSP | Automatic Weapons Self-Propelled |