| Abbreviation | Definition |
|---|---|
| ACPS | American Connemara Pony Society |
| ACPSEM | Australasian College of Physical Scientists and Engineers in Medicine |
| ACR | Academy of the Concordant Ones of Rovigo |
| ACR | Accademia dei Concordi di Rovigo |
| ACR | Association Canadienne des Réviseurs |
| ACR | Association Canadienne des Rviseurs |
| ACR | Editors' Association of Canada |
| ACRS | Association Canadienne des Rdacteurs Scientifiques |
| ACRS | Association Canadienne des Rédacteurs Scientifiques |
| ACRS | Canadian Science Writers' Association |
| ACS | American Carbon Society |
| ACS | American Cheese Society |
| ACS | American Constitution Society |
| ACS | Association d'études canadiennes |
| ACS | Association d'tudes canadiennes |
| ACS | Association for Canadian Studies |
| ACSC | Asociacin Colombiana de Sociedades Cientficas |
| ACSC | Asociación Colombiana de Sociedades Científicas |
| ACSC | Colombian Association of Scientific Societies |
| ACSG | Association Canadienne des Sciences Géomatiques |