| Abbreviation | Definition |
|---|---|
| RUTS | Racers Under the Son |
| RV | Race Version |
| RVF | Racing Vee Four |
| RVL | Racing Victoria Limited |
| RVT | Racing V Twin |
| RVW | Radial Versus the World |
| RW | RaceWalking |
| RWD | Race Winning Designs |
| RWG | Racing With Guts |
| RWI | RaceWalking International |
| RX | Racer X |
| RXL | Racing Xperimental League |
| RXL | Racing Xperimental Liquid |
| RYR | Robert Yates Racing |
| SABER | Sweeney Automobile Building Engineered Racing |
| SABRE | St. Albans Banger Racing Equipment |
| SARL | Sport Air Racing League |
| SARRC | South Atlantic Road Racing Championship |
| SARS | Schweitzer Alpine Racing School |
| SAYRA | South Atlantic Yacht Racing Association |