| cbmv | Comic Book Millennium Collection Data |
| cbo | Microsoft Interactive Training Bookmark |
| cbor | Concise Binary Object Representation Data |
| cbs | DB/TextWorks SQL Textbase Structure Data |
| cbx | IBM Rational XDE Collaboration File |
| cbx | Westok Cellbeam Data |
| cbxx | Westok Cellbeam Data |
| cc | STK City Database Counties |
| cc1 | Briggs Softworks Calendar Commander Data |
| cc1 | CARE-S InfoWorks Chemical Oxygen Detail Data |
| cc2 | Calendar Commander v2 Calendar Data |
| cc3 | CUEcards Data |
| cc4 | Crossword Compiler v4 Crossword Data |
| cca | cc:Mail Archive |
| ccad | Claris CAD Data |
| ccc | Microsoft Comic Chat Conversation Data |
| ccd | SmartWare Compiled Cartridge Descriptor |
| cce | Cumulus 6 Category Export Data |
| ccf | Cryptload Container Format File |
| ccf | Cumulus Catalog Data |
| cch | .NET Security Cache |
| cch | PhotoModeler Photo Chip Data |
| ccj | Compiled Crossword Applet |
| ccj | Corticon Server Rulesets Data |
| cck | COMcheck Data |
| ccl | CFX CCL File |
| ccld | Construction Clouds Data |
| ccm | Lotus CC:Mail |
| ccm | Multimedia Fusion Custom Menu Data |
| ccmg | STAR-CD v4 Solver Ready Geometry Data |
| ccmp | STAR-CD v4 Results Data |
| ccmt | STAR-CD v4 Transient Data |
| ccp4 | Collaborative Computational Project Number 4 Format Data |
| ccr | ASTM Continuity of Care Record |
| ccrf | Saba Centra Recording Studio Recording |