| Abbreviation | Definition |
|---|---|
| APFTU | Andhra Pradesh Federation of Trade Unions |
| APMEU | Asia Pacific Model European Union |
| APMU | Assam Petroleum Mazdoor Union |
| APPU | Asian Pacific Parliamentarians Union |
| APPU | Asian Pacific Postal Union |
| APRU | Australian Police Rugby Union |
| APSU | AugusCo Past Students Union |
| APTL | Assembly of Professionals and Technicians in Lebanon |
| APWU | American Postal Workers Union |
| ARECU | Alabama River Employees Credit Union |
| ARECU | Alabama Rural Electric Credit Union |
| ARFU | Alberta Rugby Football Union |
| ARFU | Asian Rugby Football Union |
| ARFU | Auckland Rugby Football Union |
| ARGM | ARaGMatorio |
| ARU | American Railway Union |
| ARU | Army Rugby Union |
| ARU | Australian Railways Union |
| ASBU | Arab States Broadcasting Union |
| ASCU | African Studies Course Union |