| Abbreviation | Definition |
|---|---|
| GCSF | Gulf, Colorado and Santa Fe Railway |
| GCSR | Gulf Colorado and San Saba Railway |
| GCSR | Gulf, Colorado and San Saba Railway |
| GCSU | G.C.S. Containers Service |
| GCSU | G.C.S. Containers Service, S. A. |
| GCT | Grand Central Terminal |
| GCTU | Gulf Container Lines |
| GCTX | General Chemical Corporation |
| GCW | Garden City Western Railway |
| GCW | Garden City Western Railway Company |
| GCX | Alltank Equipment Co. General Chemical Division (Honeywell) |
| GCX | Alltank Equipment Corporation |
| GCXU | Ocean Network Express |
| GCXU | Ocean Network Express Holdings Ltd |
| GDCX | General American Marks (GATX Corporation) |
| GDCX | General American Marks Company |
| GDIX | Grimmel Industries |
| GDJX | Grimmel Industries |
| GEAX | GE Rail Services |
| GEAX | Trinity Rail Management Incorporated |