| Abbreviation | Definition |
|---|---|
| ARAB | Royal Association of Belgian Actuaries |
| AraGes | Arachnological Society |
| AraGes | Arachnologische Gesellschaft |
| ARB | Académie Royale des Sciences, des Lettres, et des Beaux-Arts de Belgique |
| ARB | Acadmie Royale des Sciences, des Lettres, et des Beaux-Arts de Belgique |
| ARB | Royal Academy of Science, Humanities and Fine Arts of Belgium |
| ARC | Académie Royale des Arts du Canada |
| ARC | Acadmie Royale des Arts du Canada |
| ARC | Royal Canadian Academy of Arts |
| ARCS | Anglia Regional Co-operative Society |
| ARET | Assocation for Research in Toxicology |
| ARET | Association pour la Recherche en Toxicologie |
| ARHP | Association of Reproductive Health Professionals |
| ARHS | Anthracite Railroads Historical Society |
| ARHS | Australian Railway Historical Society |
| ARI | Air-Conditioning and Refrigeration Institute |
| ARIMS | Arthur Rubinstein International Music Society |
| ARLS | Alberta Regional Lily Society |
| ARLS | Amateur Radio Lighthouse Society |
| ARMB | Académie Royale de Médecine de Belgique |