| Abbreviation | Definition |
|---|---|
| QUAX | Quality Rail Services |
| QXA | Test Train Coach |
| QXV | Training and Instruction Coach |
| R | Rail |
| R | Railroad |
| R | Refrigerator car |
| RAB | Rail Alignment and Benefits |
| RACN | Raccoon River Railroad |
| RACX | General Electric Rail Services Corporation |
| RACX | General Electric Railcar Services Corporation |
| RAHX | Rohm and Haas |
| RAHX | Rohm and Haas Company |
| RAIB | Rail Accident and Investigation Branch |
| RAIB | Rail Accident Incident Board |
| RAIB | Rail Accident Investigation Branch |
| RAILROADS | Railroading |
| RAILS | Railroad Access and Increased Line Safety |
| RAIX | Union Carbide |
| RAIX | Union Carbide Corporation |
| RAJX | Rail Logix Alamo Junction |