| Abbreviation | Definition |
|---|---|
| CWRL | Central Western Railway Corporation |
| CWRO | Cleveland Works Railway |
| CWRY | Commonwealth Railway |
| CWRY | Commonwealth Railway Incorporated |
| CWRZ | Providence and Worcester Railroad |
| CWRZ | Providence and Worcester Railroad Company |
| CWSX | United States Steel Corporation (Cardella Waste Service of New Jersey) |
| CWTX | ChemWest Industries |
| CWTX | ChemWest Industries Incorporated |
| CWTZ | Con-Way Truckload Services |
| CXCU | Matson Navigation |
| CXCZ | CSX Lines |
| CXIX | Chemical Exchange Industries |
| CXPZ | CSX Transportation |
| CXPZ | CSX Transportation Incorporated |
| CXRZ | CSX Transportation |
| CXRZ | CSX Transportation Incorporated |
| CXVZ | CSX Intermodal |
| CXVZ | CSX Intermodal Incorporated |
| CYAU | Cyanco International |