| Abbreviation | Definition |
|---|---|
| A2C2 | All American Cannabis Club |
| AA | Action Adventure |
| AA | Alternative Armies |
| AAAA | Alberta Aerial Applicators Association |
| AAACS | Alberta Association of Automobile Clubs Society |
| AABF | Albuquerque Antiquarian Book Fair |
| AACC | All American Corvette Club |
| AACG | Awesome Autographs Collectors Group |
| AACTS | Association of Arms Collectors and Target Shooters |
| AADB | Annual Average Daily Bicyclists |
| AADC | Adelaide Advertising Design Club |
| AAMC | American Alliance for Medical Cannabis |
| AAMS | American Air Mail Society |
| AAOC | Amigos Agenda OCLC Connection |
| AAOCC | All Avondale Owners Caravan Club |
| AASC | Ann Arbor Stamp Club |
| AAVA | Associaci Andorrana de Vehicles Antics |
| AAWC | Ann Arbor Wine Club |
| AB | Antique Brass |
| ABA | American Breweriana Association |