| Abbreviation | Definition |
|---|---|
| RSDR | Rail Safety Data Report |
| RSFZ | TAL International |
| RSFZ | Transamerica Leasing Incorporated |
| RSG | Rail Supply Group |
| RSG | Rail-Supported Gantry |
| RSI | Railway Supply Institute |
| RSI | Return and Schedule Information |
| RSIP | Rail Safety Improvement Program |
| RSIZ | Rail Services |
| RSIZ | Rail Services Incorporated |
| RSL | Rail Safety Law |
| RSLX | RSL Corporation |
| RSM | Railroad Switching Service of Missouri |
| RSM | Railroad Switching Service of Missouri Incorporated |
| RSNC | Railways Staff National Council |
| RSNR | Red Springs and Northern Railroad |
| RSOR | Riceboro Southern Railway |
| RSOX | General Electric Rail Services Corporation |
| RSP | Roscoe Snyder and Pacific Railway |
| RSP | Roscoe, Snyder and Pacific Railway |