| Abbreviation | Definition |
|---|---|
| CRF | Central Repair Facility |
| CRIS | Carrier Route Information System |
| CRM | Courtesy Reply Mail |
| CRRR | Certified / Return Receipt Requested |
| CRT | Court |
| CSI | Customer Satisfaction Index |
| CSWY | CauseWay |
| CSZ | City, State, and Zip code |
| CT | Court |
| CTC | Crushed, Torn, and Curled |
| CU | Cuba |
| CV | Cape Verde |
| CV | Cove |
| CX | Christmas Island |
| CY | Cyprus |
| CZ | Czech Republic |
| DAL | Detached Address Label |
| DAS | Density Analysis System |
| DBMC | Destination Bulk Mail Center |
| DDE/DR | Distributed Data Entry and Distributed Reporting |