| cct | MicroSim PCBoard Design Information |
| cct | Vector CAD Template |
| ccu | CryptLoad Update Data |
| ccv | SAP Business Objects Crystal Vision Report |
| ccw | Crossword Compiler Crossword File |
| ccwsln | Connected Components Workbench Data |
| ccx | CorelDraw Clipart Data |
| ccz | Client-Course Manager Customized Report Distribution Data |
| cd | STK City Database Main File |
| cd1 | DATAIR Cafeteria Document System Data |
| cd2 | DATAIR Cafeteria Document System Custom Data |
| cdb | CardScan Contacts Database |
| cdb | FreeOTFE Key Data |
| cdb | Sybase PowerDesigner Conceptual Data Model Backup |
| cdb | Symbian OS Phonebook Data |
| cdbcmsg | CIM Database CMSG Data |
| cdc | AutoCAD DesignCenter Preview Cache |
| cdc | Chromeleon Device Driver Configuration |
| cdc | CLAN Debug Data |
| cdc | Ovation 1 Style Sheet |
| cdcom | Circuit Diagram Compiled Components File |
| cdd | Cadifra Diagram Data |
| cdd | Chromeleon Device Driver |
| cde | CADKEY Dynamic Extension |
| cded | Canadian Digital Elevation Data |
| cdf | Affymetrix Chip Description File |
| cdf | ANDI/netCDF Chromatography Data |
| cdf | CryENGINE Character Definition Data |
| cdf | ECMG Content Definition File |
| cdf | InstallShield Components Definition |
