| Abbreviation | Definition |
|---|---|
| NREX | National Railway Equipment |
| NREX | National Railway Equipment Company |
| NRHS | National Railway Historical Society |
| NRHX | National Railway Historical Society |
| NRI | Nebkota Railway |
| NRI | Nebkota Railway Incorporated |
| NRIU | National Refrigerants |
| NRIX | National Refrigerants |
| NRIX | National Refrigerants Incorporated |
| NRL | National Railroad Leasing |
| NRLX | NorRail |
| NRLX | NorRail Incorporated |
| NRNY | Northern Railroad (New York) |
| NRPC | National Railroad Passenger Corporation |
| NRPX | Northrop Corporation |
| NRR | Nobles Rock Railroad |
| NRRR | Nobles Rock RailRoad |
| NRSU | Nippon Riku-un Sangyo |
| NRSU | Nippon Riku-un Sangyo Company |
| NRTX | Music City Star |