| Abbreviation | Definition |
|---|---|
| CVTC | Community Volunteer Transportation Company |
| CVTCS | Continuously Variable Valve Timing Control System |
| CVTS | Collaborative Visitor Transportation Survey |
| CW | Continuous Wave |
| CWA | Center Weather Advisory |
| CWMR | Central Wisconsin Model Railroaders |
| CWP | Central Weather Processor |
| CWR | Central Wisconsin Route |
| CWR | Continuous Welded Rail |
| CWSU | Center Weather Service Unit |
| CWT | Compensated Work Therapy |
| CWY | Clearway |
| CX | Cathay Pacific Airways |
| CZ | Condition Zero |
| D | Diesel |
| D | Distance |
| D&H | Dangerous and Hazardous |
| D1 | First Coast Guard District |
| D11 | Eleventh Coast Guard District |
| D13 | Thirteenth Coast Guard District |