| Abbreviation | Definition |
|---|---|
| EPRU | Eastern Pennsylvania Rugby Union |
| EPRU | Eastern Province Rugby Union |
| ERCC | European Rugby Challenge Cup |
| ERCC | European Rugby Champions Cup |
| FFR | Fédération française de rugby |
| FONR | Friends of Newport Rugby |
| FORU | Federation of Oceania Rugby Unions |
| FPR | Federação Portuguesa de Rugby |
| FRCV | Federacion de Rugby de la Comunidad Valenciana |
| FRR | Federatia Romana de Rugby |
| GAGR | Green and Gold Rugby |
| GBWR | Great Britain Wheelchair Rugby |
| GBWR | Great British Wheelchair Rugby |
| GCRL | Gold Coast Rugby League |
| GRRA | Glendale Raptors Rugby Academy |
| HRFC | Harvard Rugby Football Club |
| IRB | International Rugby Board |
| IRPA | International Rugby Players Association |
| IRPA | International Rugby Players' Association |
| ITRA | Irish Tag rugby association |