| Abbreviation | Definition |
|---|---|
| SGIX | LPG Transportation |
| SGIX | LPG Transportation, Inc. (formerly Vision Energy Minnesota, Incorporated) |
| SGLR | Seminole Gulf Railway |
| SGLR | Seminole Gulf Railway L. P. |
| SGR | Seminole Gulf Railway |
| SGRX | Skip Gibbs |
| SGSX | Terra International |
| SGSX | Terra International Incorporated |
| SGTU | Sogotra Limited |
| SGVY | Saginaw Valley Railway |
| SGVY | Saginaw Valley Railway Company Incorporated |
| SH | Steelton and Highspire Railroad |
| SH | Steelton and Highspire Railroad Company |
| SHAX | Sherwin Alumina |
| SHJU | SHJ Containers |
| SHLX | Procor Limited |
| SHOU | Shipper Owned Container |
| SHPX | ACF Industries Incorporated |
| SHPX | ACF Industries Shippers Car Line Division |
| SHQX | American Railcar Industries |