| Abbreviation | Definition |
|---|---|
| RWY | Runway |
| RXA | Rear Cross Assembly |
| RXB | Rear Cross Bar |
| RXG | Reference Extra Grade |
| RXL | Racing Experimental Liquid-cooled |
| RXP | RouteXpress Perishable |
| RXV | Rear Crossview Mirror |
| RXY | Stability Coefficient of X and Y |
| S | Slow |
| S | Speed |
| S | Stopped |
| S | Storage |
| S | Supercharger |
| S/C | Supercharged |
| S/H | Shipping / Handling |
| SA | Shipping Agent |
| SA | Shipyard Agreement |
| SA | Slow Away |
| SA | Split Apron |
| SA | Surface Accessibility |