| ccm | Multimedia Fusion Custom Menu Data |
| ccm | Lotus CC:Mail |
| ccmg | STAR-CD v4 Solver Ready Geometry Data |
| ccmp | STAR-CD v4 Results Data |
| ccmt | STAR-CD v4 Transient Data |
| ccr | ASTM Continuity of Care Record |
| ccrf | Saba Centra Recording Studio Recording |
| ccrz | Saba Centra Recording Studio Recording |
| ccv | SAP Business Objects Crystal Vision Report |
| ccw | Crossword Compiler Crossword File |
| ccz | Client-Course Manager Customized Report Distribution Data |
| cd | STK City Database Main File |
| cdb | Sybase PowerDesigner Conceptual Data Model Backup |
| cdbcmsg | CIM Database CMSG Data |
| cdcom | Circuit Diagram Compiled Components File |
| cde | CADKEY Dynamic Extension |
| cded | Canadian Digital Elevation Data |
| cdf | ANDI/netCDF Chromatography Data |
| cdf | netCDF Data |
| cdf | ECMG Content Definition File |
| cdf | Affymetrix Chip Description File |
| cdf-ms | ClickOnce Compiled Manifest |
| cdfx | Cindex Data |
| cdl | Common Data Form Language File |
| cdm | Sybase PowerDesigner Conceptual Data Model |
| cdmp | WCS Device Model Profile |
| cdoc | DigiDoc Crypted Document |
| cdrx | Bosch Crash Data Retrieval Data |
| cdss | CorelDRAW Style Sheet |
| cdv | CatDV Catalog |
| cdv | Broken Cross Disk Manager v1 Database |
| cdws | CorelDraw X7 Workspace |
| cdx | dBASE Compound Index |
| cdx3 | Cochlear Data Exchange File |
| cea | Compressed ENVIS Archive |