| 10080 | A weak time counted in minutes. | |
| 208 | Tuonane | |
| 5W1H | Who, What, When, Where, Why, How | |
| 5W2H | Who, What, When, Where, Why, How, and How Much | |
| 8CT | 8th Congress of Toxicology | |
| A&P | Atlantic and Pacific | |
| a/s | aktieselskab | |
| A0 | international paper sizes | |
| A2030SD | Agenda 2030 Sustainable Development (UN) | |
| A4NH | Agriculture for Nutrition and Health | |
| AA | Accountant-administratieconsulent (Netherlands) | |
| AA | Alcoholics Anonymous | |
| AAAASFI | American Association for Accreditation for Ambulatory Surgery Facilities International | |
| AAAI | American Aerobics Association International | |
| AAAI | American Aerobic Association International | |
| AAAQ | Association des abattoirs avicoles du Québec | |
| AAB | Anticlinal Aguada Bandera | |
| AABA | Asociacion de Abogados de Buenos Aires | |
| AABF | Avusturya Alevi Birlikleri Federasyonu | |
| AABF | Association Artistique de la Banque de France | |
| AACATK | Assembly Area Counter Attacking Force (NATO) | |
| AACCI | American Association of Cereal Chemists International | |
| AACI | American Accreditation Commission International | |
| AADF | Albanian-American Development Foundation | |
| AAHAA | Aahaa NewsPaper In Hindi |
| AAI | ActionAid International | |
| AAIA | American Association for International Aging | |
| AAIC | Aram Allied International Corporation | |
| AAIC | Alzheimer’s Association International Conference | |
| AAII | Ad Astra International Inc | |
| AAIP | Alumni Affairs and International Programs | |
| AAIP | Alumni Affairs and International Programmes | |
| AAIP | Assuring Autonomy International Programme | |
| AAIS | Atlas Accuracy International Spigot | |
| AAIS | Arab African International Securities | |
| AAIS | Al-Andalus International School | |
| AAIS | Atlanta Adventist International School | |
| AALA | Afro Asian and Latin America | |
| AAMI | Anthony & Associates Mentoring Institute | |
| AANI | Artist Alley Network International | |
| AANI | Agra Aqua Network International | |
| AAP | Aho Aho Power | |
| AAP | Ao Agra Pagalkhana (Gujarati) | |
| AARD | Dutch for ‘earth’ | |
| AAUA | Adekunle Ajasin University Akungba | |
| AB | Algemeen Bestuur | |
| ABAI | Association for Behavior Analysis International | |
| ABBI | Ambassadors Bridge Builders International | |
| ABBI | Access Beyond Boundaries International | |
| Abbr | Abbreviations |
| ABE | Allgemeine Betriebs Erlaubnis | |
| ABIC | Association of Bermuda International Companies | |
| ABIC | Action for a Better International Community | |
| ABIC | Agricultural Bioscience International Conference | |
| ABIC | Aquatic Biodiversity International Conference | |
| ABIL | Associated Biscuits International Limited | |
| ABIM | American Baptist International Ministries | |
| ABIO | Ai Bambini In Ospedale (Finnish) | |
| ABPI | Associated Business Publications International | |
| ABSI | American Boarding Schools International | |
| AC | Autoclave | |
| ACA | Anti-Corruption Agency | |
| ACAU | A Child Among Us (international child adoption agency) | |
| ACCE | Asian Centre For Certification And Education Of Addiction Professionals | |
| ACCID | Arts Culture and Communities in International Development | |
| ACFI | Alliance Cultural Foundation International | |
| ACFID | Australian Council For International Development | |
| ACHI | A Corporate Hallmark of International | |
| ACI | Airports Council International | |
| ACI | Airport Council International | |
| ACI | Accounting Compliance International | |
| ACIAM | Atlanta Center for International Arbitration and Mediation | |
| ACIAR | Australian Center for International Agricultural Research | |
| ACIB | Associació comerciants industrials i botiguers de Begues (Catalan) | |
| ACICU | Accrediting Commission of International Colleges and Universities |
