# List of acronyms: A

This list contains acronyms, initialisms, and pseudo-blends that begin with the letter A.
For the purposes of this list:
* acronym = an abbreviation pronounced as if it were a word, e.g., SARS = severe acute respiratory syndrome, pronounced to rhyme with cars
* initialism = an abbreviation pronounced wholly or partly using the names of its constituent letters, e.g., CD = compact disc, pronounced cee dee
* pseudo-blend = an abbreviation whose extra or omitted letters mean that it cannot stand as a true acronym, initialism, or portmanteau (a word formed by combining two or more words).
    (a) = acronym, e.g.: SARS – (a) severe acute respiratory syndrome
    (i) = initialism, e.g.: CD – (i) compact disc
    (p) = pseudo-blend, e.g.: UNIFEM – (p) United Nations Development Fund for Women
    (s) = symbol (none of the above, representing and pronounced as something else; for example: MHz – megahertz)
Some terms are spoken as either acronym or initialism, e.g., VoIP, pronounced both as voyp and V-O-I-P.
(Main list of acronyms)
* a – (s) Atto-
* A – (s) Ampere

## A0–9

* A1C – Airman First Class
* A2ATD or A$^2$ATD – (i) Anti-Armour Advanced Technology Demonstration
* A2C2 or A$^2$C$^2$ – (i) Army Airspace Command and Control
* A3 – many, including a European larger than standard office paper size
* A4 – many, including a European standard office paper size; see entry
* A10 – (i) Atlantic 10 Conferencee

## AA

* aa – (s) Afar language (ISO 639-1 code)
* aA – (s) Attoampere
* AA
** (i) achieved availability
** Alcoholics Anonymous
** (s) Armed Forces Americas (postal symbol)
** Aruba (FIPS 10-4 territory code)
** (i) assembly area
** Automobile Association
** avenue of approach
** American Airlines
** Aerolíneas Argentinas
* AAA
** (i) administration, authorization, and authentication
** American Automobile Association ("Triple-A")
** anti-aircraft artillery
** Amateur Athletic Association (of England)
** Asistencia Asesoría y Administración (Spanish, "Assistance, Consulting, and Administration" — original name of Mexican professional wrestling promotion Lucha Libre AAA Worldwide)
* AAAI – (i) Association for the Advancement of Artificial Intelligence, formerly American Association for Artificial Intelligence
* AAAS – (i) American Association for the Advancement of Science
* AAAV – (i) Advanced Amphibious Assault Vehicle
* AABN – (i) African Aurora Business Network
* AABP – (i) American Association of Bovine Practitioners
* AAC
** (i) American Athletic Conference
** Army Air Corps (British Army)
* AACL – (i) Albanian American Civic League
* AACCS – (i) American Association of Christian Colleges and Seminaries
* AAD
** (i) analogue-analogue-digital (CD quality)
** Australian Antarctic Division
* AADHD – Adult attention deficit hyperactivity disorder
* AADT – (i) annual average daily traffic
* AADAC – (a) Alberta Alcohol and Drug Abuse Commission
* AADC
** (i) area air defense commander
** (i) amino acid decarboxylase
** (i) aromatic L-amino acid decarboxylase
** (i) Australian Antarctic Data Centre
* AAFC
** (i) U.S. Army Air Corps Ferrying Command (1941–1942)
** All-America Football Conference (1946–1949)
* AAFES – (i) Army and Air Force Exchange Service
* AAI – (i) applied artificial intelligence
* AAIS – (i) advanced airborne interceptor simulator
* AAM – (i) air-to-air missile
* AAMOF – (i) as a matter of fact
* AAN – (i) American Academy of Nursing
* AANEAS – (a) Anglo-Australian Near-Earth Asteroid Survey
* AAODL – (i) Atmospheric Aerosols and Optics Data Library
* a.a.p. – (i) Associated Artists Productions (former film distributor)
* AAP
** (i) advanced acquisition plan
** Allied administrative publication
** American Academy of Pediatrics
* AAPC – (i) Accounting and Auditing Policy Committee
* aar – (s) Afar language (ISO 639-2 code)
* AAR
** (i) after-action review
** Association of American Railroads
* AARP – (i/s) American Association of Retired Persons (now officially known only by the initials)
* AAS
** (i) Advanced Automation System
** American Astronomical Society ("double-A-S")
* AASPEM – (i) advanced air-to-air system performance evaluation model
* AAT – (i) Australian Antarctic Territory
* AAV – (i) Amphibious Assault Vehicle
* AAWC – (i) anti-air warfare commander

## AB

* ab – (s) Abkhaz language (ISO 639-1 code)
* AB
** (i) Able Seaman (both the rank and the occupation)
** (s) Alberta (postal symbol)
* ABA
** (i) Adriatic Basketball Association
** American Bar Association
** American Basketball Association
** American Beverage Association
** American Bicycle Association
** American Birding Association
** Australian Broadcasting Authority
* ABB – (i) ASEA Brown Boveri (Swiss-Swedish multinational company)
* ABBA – (a) Agnetha, Benny, Björn, Anni-Frid (Swedish pop group)
* ABC
** (i) abstinence, be faithful, condoms
** Active Body Control
** airway, breathing, circulation (see CPR)
** Alcoholic Beverage Control (or Alcoholic Beverage Commission)
** alien big cat
** always be careful
** American Bird Conservancy
** American-born Chinese
** American Broadcasting Company
** anti-lock brake controller
** Associated British Cinemas
*** ABC Cinemas
*** ABC Weekend TV (Associated British Cinemas (Television) Ltd / ABC Television Ltd)
** Associated British Corporation (ABC Television Films Ltd)
** Atanasoff–Berry Computer
** Atlantic Baptist College
** atomic, biological, chemical (see NBC)
** Australian Broadcasting Corporation
** already been chewed gum
* ABCA
** (i) American, British and Canadian Armies (originally)
** Army Bureau of Current Affairs
* ABCS – (i) (U.S.) Army Battle Command System
* ABET – (a) Accreditation Board for Engineering and Technology
* ABFIST – (i) Advanced Bradley Full Crew Interactive Skills Trainer
* ABGI – (i) Addington-Barker Group International
* ABIN – (a) Agência Brasileira de Inteligência (Brazilian Intelligence Agency)
* abk – (s) Abkhaz language (ISO 639-2 code)
* ABL – (i) American Basketball League
* ABLE
** (a) Achieving a Better Life Experience Act, a U.S. law that established tax-advantaged accounts for the benefit of individuals with disabilities
** AirBorne Law Enforcement (police air support unit)
* ABM – (i) anti-ballistic missile – Asynchronous Balanced Mode – automated banking machine
* ABMC – (i) American Battle Monuments Commission
* ABN
** (i) Australian Business Number (a number issued by the Australian government as registration of a business and used for taxation purposes)
** Advance Beneficiary Notice of Non-coverage (a form used in health insurance)
* ABPI – (i) Association of the British Pharmaceutical Industry
* ABRSM – (a) Associated Board of the Royal Schools of Music
* ABS
** (i) acrylonitrile butadiene styrene
** anti-lock braking system
* ABSA – (a) Amalgamated Banks of South Africa ("ab-sa")
* ABSTRIPS – (p) abstraction-based STRIPS
* ABV – (i) Alcohol by volume
* ABW – (s) Aruba (ISO 3166 trigram)

## AC

* aC – (s) Attocoulomb
* Ac – (s) Actinium
* AC
** (i) Adriamycin-Cyclophosphamide (chemotherapy)
** Air Conditioning
** Aircraftman
** Alternating Current
** Altocumulus
** ante Christum (Latin, "before Christ"; see BC)
** ante cibum (Latin, "before meals")
** (s) Antigua and Barbuda (FIPS 10-4 country code)
** (i) Associazione Calcio (Italian, "football (soccer) club")
* A/C – (i) Air Conditioned/Conditioning – Aircraft
* AC1 – Aircraftman 1st Class
* AC2 – Aircraftman 2nd Class
* ACA
** Affordable Care Act, shorthand for the Patient Protection and Affordable Care Act, commonly called "Obamacare"
** (i) Airspace Control Authority
** Airspace Co-ordination Area
** A Current Affair
* ACAB, short for "All Cops Are Bastards"; used as a political slogan associated with dissidents who are opposed to the police.
* ACARS – (a) Aircraft Communications Addressing and Reporting System
* ACAS
** (a) Aboriginal Children's Advancement Society
** Advisory, Conciliation and Arbitration Service
* ACB – (i) Asociación de Clubes de Baloncesto (Spanish for "Association of Basketball Clubs")
* ACC
** (i) U.S. Air Combat Command
** Air Component Commander
** Alpine Club of Canada
** Altocumulus castellanus
** Area control center
** Atlantic Coast Conference
** Automatic climate control
* ACCA
** (i) The Association of Chartered Certified Accountants
** Automatic Cloud Cover Assessment
* ACCAC – (a) Awdurdod Cymwysterau, Cwricwlwm ac Asesu Cymru (Qualifications, Curriculum and Assessment Authority for Wales)
* ACCD – American Coalition of Citizens with Disabilities
* ACCS – (i) Air Communications and Control Squadron
* ACDA – (i) Arms Control & Disarmament Agency
* ACDC
** (i) Alternating Current Direct Current
** the name of an Australian rock music band
** a term for a bisexual person
* A/Cdre – Air Commodore
* ACDT
** (a) Apple Certified Desktop Technician
** (a) Australian Central Daylight Time
* ACE
** (a) Air Combat Emulator (computer game)
** Allied Command Europe
** Angiotensin-converting enzyme
** Armored Combat Earthmover
** Automatic Computing Engine
* ACE2 – (i/p) Angiotensin-converting enzyme 2 (pronounced "ace-two")
* ACES
** (a) Aerolíneas Centrales de Colombia (Spanish, "Central Colombian Airlines")
** Auxiliary Campus Enterprises and Services of Alfred State College
* ACF
** (i) Administration for Children and Families
** American Car and Foundry
** American Culinary Federation
* ACH – (i) Automated clearing house
* ACHT – (i) Average Call Hold Time
* ACID – (a) Atomicity, Consistency, Isolation, and Durability (in databases)
* ACINT – (p) Acoustic Intelligence
* ACK – (p) Acknowledge (telecommunications; cf. NAK)
* ACL
** (i) Access Control List
** Anterior cruciate ligament; the initialism can also refer to an injury to this ligament
** Atlantic Coast Line Railroad
* ACLJ – (i) American Center for Law and Justice
* ACLOS – (i) Automatic CLOS (missile control system)
* ACLS – (i) American Council of Learned Societies
* ACLU
** (i) American Civil Liberties Union
** American Communist Lawyers Union (pejorative slang for the above)
* ACM – many, including Association for Computing Machinery; see entry
* ACMC – (i) (U.S.) Assistant Commandant of the Marine Corps
* ACN
** (i) Airborne Communications Node
** Australian Company Number (number issued by the Australian government as registration of a limited liability company)
* ACNA
** (i) Anglican Church in North America
** (i) ACNA (company) - National Dyes Company and Affiliates
* ACO – (i) Airspace Control Order
* ACOBA – (a) Advisory Committee on Business Appointments
* ACOG – (a) American College of Obstetricians and Gynecologists
* ACOM – (p) (U.S.) Atlantic Command
* ACORN – (a) Association of Community Organizations for Reform Now
* ACP
** (i) African, Caribbean and Pacific Group of States
** Air Control Point
* ACR – (i) Advanced Concepts and Requirements
* ACRI – (p) African Crisis Response Initiative
* ACRT – (i) Advanced Concepts Research Tool simulator
* ACS
** (i) Affiliated Computer Services (NYSE ACS)
** Alaska Communications Service
** American Cancer Society
** American Chemical Society
** Association of Caribbean States
** Australian Computer Society
* ACSC – (i) Army Command and Staff College (various nations)
* ACST – (i) Australian Central Standard Time
* ACST – (i) American Cooperative School of Tunis
* ACT
** (i) Adaptive Control of Thought (cognitive model)
** American College Test (ing Program)
** Australian Capital Territory (also postal symbol)
* ACT UP – (a) AIDS Coalition to Unleash Power
* ACTD – (i) Advanced Concept Technology Demonstration
* ACTF
** (i) (U.S.) Army Constructive Training Federation
** Australian Children's Television Foundation
* ACT-R – (i) ACT-Rational (cognitive model)
* ACT-R/PM – (i) ACT-R/Perceptual-Motor (cognitive model)
* ACTU – (i) Australian Council of Trade Unions
* ACU
** (i) Abilene Christian University
** American Conservative Union
* ACUF
** (i) BGN Advisory Committee on Undersea Features
** (a) American Conservative Union Foundation
* ACV – (i) Armoured Combat Vehicle

## AD

* AD – (i) Air Defence – (s) Andorra (ISO 3166 digram) – (i) Anno Domini (Latin, "In the year of our Lord")
* A/D – (i) Analog/Digital
* ADA
** (i) Air Defence Artillery
** American Dental Association
** Assistant District Attorney
** Americans with Disabilities Act (see also the similar but non-acronymic Ada programming language)
** ADA Cryptocurrency token for Cardano blockchain
* ADAC – (a/i) Allgemeiner Deutscher Automobil-Club (German, "General German Automobile Club")
* ADAGE – (a) Air Defense Air to Ground Engagement (simulation)
* ADAP – (i) AIDS Drug Assistance Program
* ADAS – (a/i) Asiago-DLR Asteroid Survey
* ADAT – (i) Alesis Digital Audio Tape (recording format)
* ADatP – (p) Automated Data Processing
* ADATS –
** (i) Agricultural Development and Training Society
** Air Defence Anti-Tank System
** Australian Defence Air Traffic System
* ADB – (i) Asian Development Bank
* ADB- All da best/All the best - texting slang
* ADC –
** (i) Aide De Camp
** U.S. Air Defense Command (1946–1992)
** Apple Display Connector
* ADCTS – (i) Advanced Distributed Combat Training System
* ADD –
** (i) Analog Digital Digital (CD quality)
** Attention-Deficit Disorder
** Administration on Developmental Disabilities
* ADDIE – (i) Analyze Design Develop Implement and Evaluate
* ADDNS – (i) Advanced Deployable Day/Night Simulation
* ADE
** (i) Algebraic differential equation
** Antibody-dependent enhancement
* ADF
** (i) Australian Defence Force
** African Development Foundation
* ADGB – Air Defence of Great Britain
* ADHD – (i) Attention-Deficit Hyperactivity Disorder
* ADHS – (i) Attention-Deficit Hyperactivity Syndrome
* ADI – (i) Acceptable/Allowable Daily Intake
* ADIZ – (a/i) Air Defence Identification Zone
* ADL – (i) Anti-Defamation League
* ad loc. – (p) ad locum (Latin, "to/at the place")
* ADM –
** (i) Administrative
** (s) Admiral, and the U.S. Public Health Service Commissioned Corps
** Archer Daniels Midland
** Assistant Deputy Minister
* ADOA – (a/i) Air Defence Operations Area
* ADP –
** (i) Adenosine DiPhosphate
** Army Doctrine Publication (UK, Canada, Australia)
** Automatic/Automated Data Processing
* ADRG – (p) Arc-second Raster Chart (ARC) Digitized Raster Graphics
* ADS –
** (a/i) Active Denial System
** Astrophysics Data System
** Attention Deficit Syndrome
* ADSR – (i) Attack, Decay, Sustain, Release (sound envelope specification)
* ADT
** (i) Abu Dhabi Terminals, operator of commercial ports in Abu Dhabi
** American District Telegraph, a former name of ADT Inc.
** Atlantic Daylight Time (UTC−3 hours)
* ADTB – (i) Army Doctrine and Training Bulletin
* adv. – (p) adversus (Latin, "against")
* ADW – (i) Air Defence Warning

## AE

* ae – (s) Avestan language (ISO 639-1 code)
* AE
** (s) Armed Forces Africa/Canada/Europe/Middle East (postal symbol)
** United Arab Emirates (ISO 3166 digram; FIPS 10-4 country code)
** (i) Artix Entertainment
** American Eagle
* A&E
** (a/i) Arts & Entertainment Network, the original name for the U.S. TV channel now known as A&E Network
** Accident and Emergency
* AEB – Autonomous Emergency Braking, see Collision avoidance system
* AED – (s) United Arab Emirates dirham (ISO 4217 currency code)
* AEDT – (a) Australian Eastern Daylight Time
* AEF – (i) American Expeditionary Force
* AEGIS – (p) Airborne Early warning Ground environment Interface Segment (fake etymology)
* AEI-T – (i) Army Enterprise Infostructure-Transport
* aeq. – (p) aequalis (Latin, "equal")
* AESR – (i) Aeronautical Equipment Service Record
* AEST – (a) Australian Eastern Standard Time
* aet. – (p) aetatis (Latin, "of age", "aged")
* aet – (i) After extra time (Football)
* AEW
** (i) Air Expeditionary Wing
** (i) Airborne early warning
** (i) Airborne electronic warfare
** (i) All Elite Wrestling (US professional wrestling promotion)

## AF

* af – (s) Afrikaans language (ISO 639-1 code)
* aF – (s) Attofarad
* AF
** (s) Afghanistan (FIPS 10-4 country code; ISO 3166 digram)
** (i) Air Force
** As fuck
* AFA
** (i) U.S. Air Force Academy
** Asociación del Fútbol Argentino (Spanish, "Argentine Football Association")
* AFAIC – (i) As Far As I'm Concerned
* AFAICT – (i) As Far As I Can Tell
* AFAIK – (i) As Far As I Know
* AFAIR – (i) As Far As I Remember/Recall
* AFAM
** (i/a) Associazione Friulana di Astronomia e Meteorologia (Italian, "Friuli Association of Astronomy and Meteorology")
** (p) Department of African and Afro-American Studies, University of North Carolina at Chapel Hill — notable for its links to the school's academic-athletic scandal in the 2010s
* AFATDS – (i) Advanced Field Artillery Tactical Data System
* AFC
** (i) American Football Conference
** Approved for construction
** Asian Football Confederation
* AFCEA – (i) Armed Forces Communications and Electronics Association
* AfD
** (i) Allianz für Deutschland ("Alliance for Germany"), former political alliance in East Germany
** Alternative für Deutschland ("Alternative for Germany"), current German political party
* AFD
** (i) Active Format Description, a technical standard for TV or set-top box decoders
** Advanced Format Drive, a type of computing storage device
** Adjustable-frequency drive
** Adult Film Database, web-based database of adult cinema
** Agence française de développement ("French Development Agency"), a French international development agency
** Alliance des forces démocratiques (French; "Alliance of Democratic Forces"), an Ivorian political alliance
** Alliance for Freedom and Democracy, an Eritrean political party
* AFDB – (i) African Development Bank
* AFES – (i) Automatic Fire Extinguishing System
* AFG – (s) Afghanistan (ISO 3166 trigram)
* AFGAM – (i) Amazon Facebook Google Apple Microsoft
* AFI
** (s) French Territory of the Afars and Issas (ISO 3166 trigram; obsolete since 1977)
** (i) "Agencia Federal de Investigaciónes" (México)
* AFIS
** (a) Automated Fingerprint Identification System
** American Forces Information Service
* AFIST – (i) Abrams Full Crew Interactive Skills Trainer
* AFJ – (i) April Fool's Joke
* AFK – (i) Away From Keyboard (Internet chat abbreviation)
* AFL
** (i) American Federation of Labor
** American Football League — either the 1960s league that merged into the National Football League, or one of several other leagues of American football
** Arena Football League
** Australian Football League
* AFL–CIO – (i) American Federation of Labor – Congress of Industrial Organizations
* AFLAC – (a) American Family Life Assurance Company of Columbus
* AFM – (i) Army Field Manual (UK; the U.S. more frequently uses just FM) – Atomic Force Microscope – Aviation Fleet Maintenance
* AFN – (s) Afghani (ISO 4217 currency code)
* AFO – (i) Association of Field Ornithologists
* AFOSR – (i) U.S. Air Force Office of Scientific Research
* AFP
** (i) Agence France-Presse (French, "French Press Agency")
** Australian Federal Police
* AFQT – (i) Armed Forces Qualification Test
* afr – (s) Afrikaans language (ISO 639-2 code)
* AFRC – (i) Air Force Reserve Command
* AFRL – (i) Air Force Research Laboratory
* AFROTC – (i) Air Force Reserve Officer Training Corps
* AFRRI – (i, U.S.) Armed Forces Radiobiology Research Institute
* AFRTS – (i) Armed Forces Radio and Television Service
* AFS
** (i) Active Front Steering
** Air Facility Sub-System
** Amniotic Fluid-derived Stem cell
* AFS&A or AFSA – (i) U.S. Air Force Studies and Analysis
* AFSC
** (i) U.S. Air Force Staff College (obsolete; replaced by JFSC)
** U.S. Air Force Systems Command
* AFSCN – (i) U.S. Air Force Satellite Control Network
* AFSPC – (i) Air Force Space Command
* AFT – American Farmland Trust
* AFV – (i) armoured fighting vehicle or America's Funniest Home Videos
* AFWA
** (a) Air Force Weather Agency
** Association of Fish and Wildlife Agencies

## AG

* ag – (s) Attogram
* Ag – (s) Silver (Latin argentum)
* AG
** (i) air gunner
** Aktiengesellschaft (German, "incorporated")
** (s) Algeria (FIPS 10-4 country code)
** Antigua and Barbuda (ISO 3166 digram)
** Assemblies of God
* AGA
** (a/i) AB Gas-accumulator ("ah-gah", Swedish company)
** Advanced Graphics Architecture
* AGARD – (a) Advisory Group for Aerospace Research and Development
* AGARDograph – (p) Advanced Guidance for Alliance Research and Development publication
* AGASA – (a) Akeno Giant Air Shower Array (cosmic ray detector)
* AGB – (i) Internal Nintendo initialism (Advanced Game Boy) for Game Boy Advance
* AGC
** (i) Apollo Guidance Computer
** Automatic Gain Control
* AGC – (i) Adjutant General's Corps (British Army)
* AGDC – (i) Australian Game Developers' Conference
* AGI – (i) Auxiliary Group Intelligence
* AGL – (i) Above Ground Level
* AGM – (i) Annual General Meeting
* AGN – (i) Active Galactic Nucleus
* AGO – (s) Angola (ISO 3166 trigram)
* AGP – (i) Accelerated Graphics Port
* AGRICOLA – (a) Agriculture Online Access
* AGS – (i) Alaska Ground Station (LandSat)
* AGTS – (i) Advanced Gunnery Training System
* AGU – (i) American Geophysical Union
* AGW – (i) Autonomous Guided Weapon

## AH

* aH – (s) Attohenry
* Ah – (s) Ampere hour
* AH – (i) Attack Helicopter
* AHA – (i) American Heart Association
* AHCPR – (i) Agency for Health Care Policy and Research (obsolete; replaced with AHRQ)
* AHEC – (i) Australian Health Ethics Committee
* AHPCRC – (i) Army High Performance Computing Research Center
* AHQ – Air Headquarters
* AHRQ – (i) Agency for Healthcare Research and Quality
* AHS – (i) American Housing Survey

## AI

* AI
** (i) Air Interdiction
** Amnesty International
** Artificial Insemination
** Artificial Intelligence
** (s) Anguilla (ISO 3166 digram)
* AIA
** (i) Aerospace Industries Association
** American Institute of Architects
** (s) Anguilla (ISO 3166 trigram)
* AIAA – (i) American Institute of Aeronautics and Astronautics
* AIC
** (i) African Independent Church
** Animal Identification Coordinator
* AICD – (i) Australian Institute of Company Directors
* AICMFP – (i) And I Claim My Five Pounds
* AID – (i) U.S. Agency for International Development
* AIDS – (a) Acquired Immune Deficiency Syndrome
* AIHW – Australian Institute of Health and Welfare
* AIM – many, including AOL Instant Messenger, Australian Institute of Management; see entry
* AIMP – (i) Aurora Incremental Modernization Project
* AIPAC – (i) American Israel Public Affairs Committee
* AIR – (i) Aircraft Inventory Record
* AIRFA – (a) American Indian Religious Freedom Act
* AIRS – (a/i) Aerometric Information Retrieval System (obsolete; replaced with AFS)
* AIS
** (i) Australian Institute of Sport
** Automatic Identification System
* AISB – (i) (British) Society for the Study of Artificial Intelligence and the Simulation of Behaviour

## AJ

* aJ – (s) Attojoule
* AJ – (s) Azerbaijan (FIPS 10-4 country code)
* Ajax – (a) Asynchronous JavaScript And XML
* AJD – (i) Astronomical Julian day
* AJP – (i) Allied Joint Publication
* AJPW – (i) All Japan Pro Wrestling

## AK

* ak – (s) Akan languages (ISO 639-1 code)
* aK – (s) Attokelvin
* AK – (s) Alaska (postal symbol)
* aka – (s) Akan languages (ISO 639-2 code)
* a.k.a. – (i) Also known as (i.e.: alias)
* AKA – (i) Above knee amputation (orthopaedic usage)
* AKDT – (p) Alaska Standard Daylight Saving Time (UTC−8 hours)
* AKST – (p) Alaska Standard Time (UTC−9 hours)
* AKP – (i) Adalet ve Kalkınma Partisi (Turkish, "Justice and Development Party")

## AL

* aL – (s) Attolitre
* Al – (s) Aluminium
* AL
** (s) Alabama (postal symbol)
** Albania (FIPS 10-4 country code; ISO 3166 digram)
** (i) Anno Lucis (Latin, "Year of Light", in Masonic tradition, most often seen on plaques bearing the founding dates of buildings, in years AD and years AL)
* ALA – (s) Åland (ISO 3166 trigram)
* ALAP – (a) As Long/Late As Possible
* ALARM – (a) Air-Launched Anti-Radar Missile
* ALB – (s) Albania (ISO 3166 trigram)
* ALCOA or Alcoa – The Aluminum Company of America, NYSE:AA
* ALD – (i) Accounting Line Designator (nuclear weapon targeting)
* ALERT – (a) Advanced Linked Extended Reconnaissance and Targeting – Attack and Launch Early Reporting to Theatre
* ALF
** (a) Africa Leadership Forum
** Alien Life Form (cf. ALF (TV series))
** Animal Liberation Front
* ALG – (s) Algeria (IOC and FIFA trigram, but not ISO 3166)
* ALGOL – (p) ALGOrithmic Language
* ALL – (s) Albanian lek (ISO 4217 currency code)
* ALOA – (i) Associated Locksmiths of America, Inc.
* ALOC
** (a) Air Lines Of Communication
** (a) Average Length of Calls
* ALP – (i) Australian Labor Party
* ALPA – (a) Air Line Pilots Association
* ALS – (i) Amyotrophic Lateral Sclerosis – Automatic Landing System
* ALSHS – (a) Abraham Low Self-Help Systems
* ALSP – (i) Aggregate Level Simulation Protocol
* ALTA – American Land Title Association
* ALTE – (a) Association of Language Testers in Europe
* ALTACS – (p) Automated decision Logic Tactical Air Combat Simulation

## AM

* am
** (s) Amharic language (ISO 639-1 code)
** Attometre
* Am – (s) Americium
* AM
** many, including Amplitude Modulation and Ante Meridiem; see entry
** (s) Armenia (FIPS 10-4 country code; ISO 3166 digram)
* AM1 – Airman 1st class
* AMA
** (i) American Medical Association
** Australian Medical Association
* AMAPS – (a) Aircraft, Missile, Avionics Performance Simulation
* AMC
** (i) Adaptive modulation and coding (digital communications)
** U.S. Air Mobility Command
** American Motors Corporation
** American Movie Classics (TV network; now known simply by the initials)
** U.S. Army Materiel Command
* AMCB – (i) U.S. Army/Marine Corps Board
* AMD
** (i) Advanced Micro Devices
** Age-related Macular Degeneration
** (s) Armenian dram (ISO 4217 currency code)
* AMF – (i) Afghan Military Force(s)
* AMFOM – (i) Advanced Missile Fly Out Model ("am-fomm")
* AMFR
** (i) Age-specific Marital Fertility Rate
** Amplitude Modulation Following Response
* AMFRS
** (i) Advanced Multi-Function Radio Frequency System
** Automatic Multisensor Feature-based Recognition System
* amh – (s) Amharic language (ISO 639-2 code)
* AML – (i) Acute Myeloid Leukaemia
* AMLCD – (i) Active Matrix Liquid Crystal Display
* AMLO
** (i) Andrés Manuel López Obrador (Mexican politician)
** Anti-Money Laundering Office — separate government agencies in Taiwan and Thailand
* AMO – (i) Atlantic Multidecadal Oscillation
* AMOLED – (i) Active-matrix organic light-emitting diode
* AMOS
** (a) Advanced MOrtar System
** Air Force Maui Optical and Supercomputing observatory
* AMP
** (i) Adenosine MonoPhosphate
** (i) Antimicrobial peptide
** Automated Mission Planner
** Anak ng Puta
** (i) Ain't My Problem
* AMRAAM – (a) Advanced Medium-Range Air-to-Air Missile
* AMRDEC – (i) U.S. Aviation & Missile Research, Development, & Engineering Center
* AMS
** (i) Agriculture Marketing Service
** American Mathematical Society
* AMSAA – (i/a) U.S. Army Materiel Systems Analysis Activity
* AMSB – (i) Aix Maurienne Savoie Basket (French basketball club)
* AMSO – (i/a) U.S. Army Model and Simulation Office
* AMSU – Advanced Microwave Sounding Unit
* AMTE – (i) UK Admiralty Marine Technology Establishment (1977–1984)

## AN

* an – (s) Aragonese language (ISO 639-1 code)
* aN – (s) Attonewton
* AN
** (s) Andorra (FIPS 10-4 country code)
** Netherlands Antilles (ISO 3166 digram)
* ANA
** (i) Administration for Native Americans
** Afghan National Army
** All Nippon Airways
** Anti-Nuclear Anti-body
** (a) Australian National Airways
** Australian Natives' Association
* ANC – (i) African National Congress
* AND – (s) Andorra (ISO 3166 trigram)
* ANFO – (i) Ammonium nitrate/fuel oil (explosive)
* ANG
** (i) Air National Guard
** (s) Angola (IOC and FIFA trigram, but not ISO 3166)
** (s) Netherlands Antillian guilder (ISO 4217 currency code)
* ANGLiCo – (p) Air/Naval Gunfire Liaison Company
* ANL – (i) Argonne National Laboratory
* ANM – (i) Acoustic Noise Monitor
* ANOVA – (p) ANalysis Of VAriance
* ANS – (i) Applied and Natural Sciences
* ANSI – (a) American National Standards Institute
* ANTM – (i) America's Next Top Model
* ANT
** (s) Netherlands Antilles (ISO 3166 trigram)
** Antigua and Barbuda (IOC trigram, but not ISO 3166 or FIFA)
* ANTY – Acronyms, No Thank You
* ANWA – (i) Augusta National Women's Amateur, a prominent American golf tournament
* ANWR – (i) Arctic National Wildlife Refuge /ˈænwɑːr/
* ANZ – (s) Australia and New Zealand Banking Group
* ANZAC – (a) Australian and New Zealand Army Corps

## AO

* AO
** (s) Angola (FIPS 10-4 country code; ISO 3166 digram)
** (i) Approach Officer (submarine)
** Area of Operations
* AOA
** (i) Air Officer in charge of Administration
** Argonne National Laboratory
** (s) Angolan kwanza (ISO 4217 currency code)
** (i) Award of Arms (heraldry)
** Angle of Attack (fluid dynamics)
* AOC
** (i) Air Operations Centre
** Air Officer Commanding
** Alexandria Ocasio-Cortez (American politician)
* AOC in C – Air Officer Commanding in Chief
* AOD – (i) Adrenalin O.D. (punk rock band)
* AOE – Area of Effect
* AOI
** (i) Angle of Incidence
** Arab Organization for Industrialization
* AOL – (i) America OnLine
* AOR – (i) Area of Responsibility
* AOSTH – (i) Adventures of Sonic the Hedgehog
* AOTS – (i) Attack of the Show!
* AOU – (i) American Ornithologists' Union

## AP

* AP
** (i) Advanced Placement
** Air Publication
** (s) Andhra Pradesh (Indian state code)
** (s) Armed Forces Pacific (postal symbol)
** (i) Associated Press
** Auto Pilot
* APA –
** (i) Acolytes Protection Agency (professional wrestling tag team)
** American Psychiatric Association
** American Psychological Association (see also APA style, a writing format developed by this body)
* APB – (i) All Points Bulletin (police jargon)
* APC
** (i) Armoured Personnel Carrier
** Armour Piercing Capped (ammunition)
* APEC – (a) Asia Pacific Economic Cooperation
* APCNR – (i) Armour-Piercing, Composite Non-Rigid (ammunition)
* APCR – (i) Armour-Piercing, Composite Rigid (ammunition)
* APDS – (i) Armour-Piercing, Discarding-Sabot (ammunition)
* APEDS – (a) AMSAA Performance Estimates Data System
* APEX – (p) Applied Physics Express
* APFSDS – (i) Armour-Piercing, Fin-Stabilised, Discarding Sabot (ammunition)
* APHA – (i) American Public Health Association
* APHE – (i) Armour-Piercing, High Explosive (ammunition)
* APHIS – (a) Animal and Plant Health Inspection Service
* API – (i) Application Programming Interface
* APL
** (i) A Programming Language
** Acute Promyeloid Leukaemia
** Anti-Personnel Landmine
** Applied Physics Laboratory (Johns Hopkins University)
* APM – (i) Advanced Power Management
* APNP – Advanced Practice Nurse Prescriber
* APOD – (i) Aerial Port (Airport) Of Debarkation
* APOE – (i) Aerial Port (Airport) Of Embarkation
* APOLLO – (a) Apache Point Observatory Lunar Laser-ranging Operation
* APP – (i) Allied Procedural Publication
* APR – (i) Annual Percentage Rate
* APS
** (i) Advanced Photo System (cf. APS-C, an image sensor format based on the size of the original APS film frame)
** American Physical Society
** Antiphospholipid Antibody Syndrome

## AQ

* AQ
** (i) AdventureQuest
** (s) American Samoa (FIPS 10-4 territory code)
** Antarctica (ISO 3166 digram)
** (i) Automatic qualifier, a term used by U.S. sports media from 1998 to 2013 to refer to the six conferences whose champions automatically entered the now-defunct Bowl Championship Series of college football
* AQIM – (i) Al-Qaeda in the Islamic Maghreb
* AQPS – (i) Autre que pur-sang (French: "Other than Thoroughbred"), designation of a type of French racehorse

## AR

* ar – (s) Arabic language (ISO 639-1 code)
* Ar – (s) Argon
* AR
** (s) Argentina (FIPS 10-4 country code; ISO 3166 digram)
** Arkansas (postal symbol)
** (i) ArmaLite Rifle (cf. ArmaLite AR-15 and AR-15 style rifle, both also referred to with the "AR" initialism)
** Armour
** (s) Arunachal Pradesh (Indian state code)
* ara – (s) Arabic language (ISO 639-2 code)
* ARAG – (a) Advanced Research and Assessment Group
* ARB – (i) Administrative Review Board
* ARBA – (a/i) Army Review Boards Agency
* ARC
** (i) Appalachian Regional Commission
** Arc-second Raster Chart
** (a) Association of Retarded Citizens, the original name of the organization now known as Arc of the United States
** (i) Athletics–Recreation Center, an indoor arena at Valparaiso University
* ARCA – (a) Automobile Racing Club of America
* ARCENT – (p) United States Army Central Command
* ARDA – (a) Advanced Research and Development Activity (became DTO 2006)
* ARE
** (i) UK Admiralty Research Establishment (1984–1991)
** (s) United Arab Emirates (ISO 3166 trigram)
* ARF – (i) ASEAN Regional Forum
* arg – (s) Aragonese language (ISO 639-2 code)
* ARG – (s) Argentina (ISO 3166 trigram)
* ARH – (s) Armed Reconnaissance Helicopter
* ARI
** (i) Acute Respiratory Infection
** U.S. Army Research Institute for the Behavioral and Social Sciences
* ARL
** (i) UK Admiralty Research Laboratory (1921–1977)
** U.S. Army Research Laboratory
** UIUC Aviation Research Laboratory
* ARM
** (a) Acorn RISC Machine, later Advanced RISC Machine (cf. Arm Ltd.)
** Anti-Radiation Missile
** Adjustable-rate mortgage
** (s) Armenia (ISO 3166 trigram)
* ARNet – (p) Acquisition Reform Network
* AROTS – Australian Rare Or Threatened Species
* ARP – (i) Address Resolution Protocol – Applied Research Programme
* ARPA – (a) Advanced Research Projects Agency
* ARRC – (i) ACE Rapid Reaction Corps
* ARRF – (i) Allied Rapid Reaction Force
* ARRL – (i) American Radio Relay League
* ARS
** (i) Agricultural Research Service
** (s) Argentine peso (ISO 4217 currency code)
* ARSC – (i) Arctic Region Supercomputing Center
* ARSPACE – (p) U.S. Army Space Command
* ART
** (a) Adaptive Resonance Theory
** Anti-Retroviral Therapy
* ARTCC – (i) Air Route Traffic Control Center
* ARWG – (i) Army Research Working Group ("are-wig")

## AS

* as
** (i) Adult swim
** (s) Assamese language (ISO 639-1 code)
** Attosecond
* aS – (s) Attosiemens
* As – (s) Arsenic
* AS
** (s) American Samoa (postal symbol; ISO 3166 digram)
** Australia (FIPS 10-4 country code)
** Assam / Asom (Indian state code)
** Advanced Subsidiary (Subsidiary version of Advanced Level, 'A'-Level)
* AS – (i) ActionScript
* A/S – (i) Anti-submarine
* A&S – (i) Armament & Standardisation
* ASA
** (i) AcetylSalicylic Acid
** American Standards Association
** Army Security Agency
** Atlantic Southeast Airlines
** Alaska Airlines (ICAO code)
* ASAP – (a) As Soon As Possible
* ASARS
** (a) Advanced Synthetic Aperture Radar System
** Airborne Search and Rescue System
* ASB – (i) Associated Student Body – Alternative Service Book (Church of England)
* asbl – (i) association sans but lucratif (French "Non-profit organisation")
* ASBO – (a) Antisocial Behavior Order
* ASCAP – (a) American Society of Composers, Authors, and Publishers
* ASCC
** (i) Army Service Component Commander
** Automatic Sequence Controlled Calculator
** Air Standardization Coordinating Committee
* ASCIET – (i) All Services Combat Identification Evaluation Team
* ASCII – (a) American Standard Code for Information Interchange
* ASC+T – (i) Anti Slip Control + Traction
* ASD
** (i) (U.S.) Assistant Secretary of Defense
** Autism spectrum disorder
* ASD(C3I) – (i) (U.S.) (Command, Control, Communications, & Intelligence)
* ASD(FMP) – (i) (U.S.) Assistant Secretary of Defense (Force Management Policy)
* ASD(HA) – (i) (U.S.) Assistant Secretary of Defense (Health Affairs)
* ASD(ISA) – (i) (U.S.) Assistant Secretary of Defense (International Security Affairs)
* ASD(ISP) – (i) (U.S.) Assistant Secretary of Defense (International Security Policy)
* ASD(LA) – (i) (U.S.) Assistant Secretary of Defense (Legislative Affairs)
* ASD(PA) – (i) (U.S.) Assistant Secretary of Defense (Public Affairs)
* ASD(RA) – (i) (U.S.) Assistant Secretary of Defense (Reserve Affairs)
* ASD(SO&HA) – (i) (U.S.) Assistant Secretary of Defense (Special Operations & Humanitarian Assistance)
* ASD(SO/LIC) – (i) (U.S.) (Special Operations & Low-Intensity Conflict)
* ASD(S&R) – (i) (U.S.) Assistant Secretary of Defense (Strategy & Requirements)
* ASD(S&TR) – (i) (U.S.) Assistant Secretary of Defense (Strategy & Threat Reduction)
* ASDIC – (a) Allied Submarine Detection Investigation Committee (Sonar)
* ASEAN – (a) Association of Southeast Asian Nations
* ASFAR – (a) Americans for a Society Free of Age Restrictions
* ASG – (i) Area Support Group
* ASIC – (a) Australian Securities & Investments Commission – (a) Aviation Security Identification Card
* ASICS – (a) Anima sana in corpore sano (Latin, "A sound mind in a sound body") (athletic shoe manufacturer)
* ASIO
** (a) Australian Security Intelligence Organisation
** Audio Stream Input/Output
* ASIP
** (i) Advanced System Improvement Program
** Army Stationing and Installation Plan
** Application-specific instruction set processor
* ASL
** (i) Above Sea Level
** American Sign Language (also known as Ameslan)
** "Age, Sex, Location?" (Internet slang)
* asm – (s) Assamese language (ISO 639-2 code)
* ASM
** (i) Air-to-Surface Missile
** (s) American Samoa (ISO 3166 trigram)
** (i) American Society for Metals
** American Society for Microbiology
** Association Sportive Montferrandaise (French, "Clermont-Ferrand Sporting Association"), as in ASM Clermont Auvergne
* ASMB
** (i) American Society for Matrix Biology
** Adult Swim Message Board
* ASME
** (i) American Society of Mechanical Engineers
** American Society of Magazine Editors
* ASMP
** (i) Air-Sol Moyenne Portée missile (French "Medium-range air to surface")
** (p) Asymmetric multiprocessing
* ASMR – Autonomous Sensory Meridian Response
* ASN – (i) Associate of Science in Nursing
* ASOC
** (a/i) Air Sovereignty Operations Centre
** Air Support Operations Centre
** Airport Security and Operations Centre
** Antarctic and Southern Ocean Coalition
** Atlanta Symphony Orchestra Chorus
** Australian Standard Offence Classification
* ASP
** (i) Active Server Pages
** American Society of Primatologists
** Ammunition Supply Point
** Application Service Provider (cf internet service provider)
** Astronomical Society of the Pacific
** Association of Surfing Professionals
* ASPI – (i) Australian Strategic Policy Institute
* ASR
** (i) Alkali-silica reaction
** Anti Slip Regulation
* ASRAAM – (a) Advanced Short-Range Air-to-Air Missile
* ASSC – (i) Association for the Scientific Study of Consciousness
* Ass Paym – Assistant Paymaster
* AST – (i) Atlantic Standard Time (UTC−4 hours)
* ASTIA – (a) Armed Services Technical Information Agency
* ASTM – (i) American Society for Testing and Materials
* ASTREA – (a) Aerial Support To Regional Enforcement Agencies (sheriff's air support unit)
* ASUN – (p) Atlantic Sun Conference, now branded as the ASUN Conference (pronounced "A-sun")
* ASUW – (p) AntiSUrface Warfare
* ASVAB–Armed Services Vocational Aptitude Battery (taken by juniors in high school in the USA)
* ASVEL – (a) Association Sportive Villeurbanne Éveil Lyonnais (Association Sportive is French for "Sporting Association"; the club was founded through the merger of AS Villeurbanne and Éveil Lyonnais)
* ASW – (i) AntiSubmarine Warfare
* ASWORG – (i) (U.S.) AntiSubmarine Warfare Operations Research Group
* ASX
** (p) Advanced Stream Redirector
** Australian Securities Exchange

## AT

* aT – (s) Attotesla
* At – (s) Astatine
* AT – (i) Anti-Tank – (s) Ashmore and Cartier Islands (FIPS 10-4 territory code) – Austria (ISO 3166 digram) – (i) Advanced Technology (IBM Personal Computer/AT)
* ATA – (i) Advanced Technology Attachment (IBM Personal Computer) – Afghan Transitional Authority – Allen Telescope Array – (s) Antarctica (ISO 3166 trigram)
* ATAC – (a) Air Transportable Acoustic Communications
* ATACMS – (p) Army TACtical Missile System
* ATAPI – (a) Advanced Technology Attachment Packet Interface
* ATAS – (a) Air-To-Air Stinger (missile)
* ATAT – (a) Aiken Tactical Airsoft Team / Star Wars vehicle
* ATB
** (i) Active Time Battle
** (s) British Antarctic Territory (ISO 3166 trigram; merged with AQ in 1979)
* ATC –
** (i) Air Traffic Control
** Air Training Corps
** U.S. Air Transport Command (1942–1948)
** Athletic Trainer, Certified (www.nata.org)
* ATCCIS – (i) Army Tactical Command and Control Information System
* ATEBAWLS – (a) Association Towards Engineers Balling at Wii Lover's Sports
* ATESS – (i) Aerospace and Telecommunications Engineering Support Squadron
* ATF
** (s) French Southern Territories (ISO 3166 trigram)
** (i) (U.S.) Bureau of Alcohol, Tobacco, Firearms and Explosives (from its previous name, which did not include "Explosives")
* ATG – (s) Antigua and Barbuda (ISO 3166 and FIFA trigram)
* ATGM – (i) Anti-Tank Guided Missile
* ATGW – (i) Anti-Tank Guided Weapon
* ATI –
** (i) Allied Telesyn International, Inc.
** (a) Array Technologies Incorporated. (ATI Technologies)
** Air Transport International - American cargo airline
* Atisbo – a Local Government Area in Nigeria named for constituent communities (Ago-Are, Tede, Irawo, Sabe, Baasi, Ofiki and Owo)
* ATK – (p) Attack
* ATL – (p) Atlanta, Georgia, the largest city and capital of Georgia; taken from the IATA code for its airport
* ATLAS –
** (a) All-Terrain Lifter Army System
** (p) Assessment Tool for LAnd Systems
* ATM –
** (i) Automated Teller Machine
** Asynchronous Transfer Mode
** At The Moment
* ATN – (s) Dronning Maud Land (ISO 3166 trigram; merged with AQ in 1983)
* ATO
** (i) Air Tasking Order
** Australian Taxation Office
* ATP
** (i) Adenosine TriPhosphate
** Allied Tactical Publication
** Ammunition Transfer Point
** Association of Tennis Professionals (cf. ATP Tour, ATP Challenger Tour, ATP Champions Tour)
* ATSD – (p) (U.S.) Assistant Secretary of Defense
* ATSDR – (i) Agency for Toxic Substances and Disease Registry
* AT&T – (i) American Telephone and Telegraph (U.S. company, also known as "Ma Bell")
* ATV
** (i) All-terrain vehicle
** Associated Television – former UK TV company
* ATWA – (a) Air, Trees, Water, Animals

## AU

* Au – (s) Gold (Latin Aurum)
* AU –
** (i) African Union (was OAU before 2000)
** American University
** (s) Astronomical Unit
** Australia (ISO 3166 diagram)
** Austria (FIPS 10-4 country code)
* AUC –
** (i) Ab Urbe Condita / Anno Urbis Conditae (Latin "from the founding of the city" / "in the year since the founding of the city") (of Rome)
** Area Under the Curve (concentration time curve; medicine)
* AUD – (s) Australian dollar (ISO 4217 currency code)
* AUG – (a) Armee-Universal-Gewehr (German, Army Universal Rifle)
* AUS – (s) Australia (ISO 3166 trigram)
* AUSCANNZUKUS – (p) Australia, Canada, New Zealand, United Kingdom, United States (security designation)
* Auslan – (p) Australian Sign Language
* AUT – (s) Austria (ISO 3166 trigram)
* AUTL – (i) Army Universal Task List

## AV

* av – (s) Avar language (ISO 639-1 code)
* aV – (s) Attovolt
* Av – (i) Aperture value (photographic mode)
* AV
** (s) Anguilla (FIPS 10-4 territory code)
** (i) Audio-Visual
** (s) Aviation
* ava – (s) Avar language (ISO 639-2 code)
* AVA – (i) American Viticultural Area
* AVB – (i) Audio Video Bridging
* AVCATT-A – (p) (U.S. Army's) Aviation Combed Arms Tactical Trainer-Aviation [Reconfigurable Manned Simulator]
* AVDLR – (p) Aviation Depot Level Repair
* ave – (s) Avestan language (ISO 639-2 code)
* AVGP – (i) Armoured Vehicle, General Purpose
* AVI – (i) Audio Video Interleave
* AVIM – (p) Aviation Intermediate Maintenance
* AVLB – (i) Armoured Vehicle Launched Body
* AVM
** (i) Air Vice-Marshal
** (p) Arteriovenous malformation
* AVO – (i) Apprehended Violence Order
* AVP – (a) Arubaanse Volkspartij
* AVP – (i) Association of Volleyball Professionals
* AVRE – (i) Armoured Vehicle Royal Engineers
* AVTB
** (i) Armoured Vehicle Test Bed
** (p) Aviation Test Bed
* AVUM – (p) Aviation Unit Maintenance
* AVUS – (a) Automobil-Verkehrs- und Übungsstraße (German, "Automobile Traffic and Training Road"; former auto racing track and current road in Berlin)
* AVVO – (a) Acute Vaginal Venereal Outbreak

## AW

* aW – (s) Attowatt
* AW – (s) Aruba (ISO 3166 digram)
* AWA – (i) American Wrestling Association
* AWACS – (a) Airborne Warning And Control System
* AWC – (i) Air Warfare Centre
* AWD – many, including All Wheel Drive; see entry
* AWE – (i/a) Advanced Warfighting Experiment
* AWG – (s) Aruban guilder (ISO 4217 currency code)
* AWOL – (a) Absent Without Official Leave / Absent WithOut Leave (military jargon)
* AWP – (p) Awaiting Parts (SM&R code)
* AWSIM – (p) Air Warfare SIMulation
* AWST – (a) Australian Western Standard Time
* AWW – (i) Above-Water Warfare

## AX

* AX – (s) Åland (ISO 3166 digram)
* AXP – (p) Ambulance eXchange Point

## AY

* ay – (s) Aymara language (ISO 639-1 code)
* AY – (s) Antarctica (FIPS 10-4 territory code)
* AYBABTU – (i) All Your Base Are Belong To Us
* aym – (s) Aymara language (ISO 639-2 code)
* AYU – (i) As Yet Unknown

## AZ

* az – (s) Azerbaijani language (ISO 639-1 code)
* AZ
** (s) Arizona (postal symbol)
** Azerbaijan (ISO 3166 digram)
** (i) Alkmaar Zaanstreek (Dutch football club)
* AZAL – Azerbaijan Airlines
* aze – (s) Azerbaijani language (ISO 639-2 code)
* AZE – (s) Azerbaijan (ISO 3166 trigram)
* AZN – (s) Azerbaijani manat (ISO 4217 currency code)
* AZUR – (p) Actions en zone urbaine (French, Urban Operations)