| Abbreviation | Definition |
|---|---|
| NS | Norfolk Southern Railway |
| NS | Norfolk Southern Railway Company |
| NSAX | National Steel Corporation |
| NSB | Norwegian State Railways |
| NSC | National Steel Car |
| NSCT | Niagara, St. Catharines and Toronto Railway |
| NSCU | Norfolk Southern Railway Company |
| NSCX | National Steel Car Corporation |
| NSCX | National Steel Car Limited |
| NSE | Network South East |
| NSFZ | Norfolk Southern Railway |
| NSGU | NBC Sports |
| NSHR | North Shore Railroad |
| NSHR | North Shore Railroad Company |
| NSL | St. Lawrence and Raquette River Railroad |
| NSLU | Norasia Services |
| NSLZ | Nestle Transportation |
| NSLZ | Nestle Transportation Company |
| NSPX | Northern States Power |
| NSPX | Northern States Power Company |