| cap | Libpcap Captured Packets |
| capt | Linrock Capito Data |
| caro | Adobe Acrobat Creator Code |
| castep | CASTEP Data |
| cat | Quicken IntelliCharge Categorization |
| cat | TINA Pro Catalog |
| cat4d | Maxon Cinema 4D Catalog |
| catalog | Catia Catalog |
| catshape | CATIA Shape Data |
| cav | Kintraks Database |
| caw | SSIS Cache Data |
| cb1 | CARE-S InfoWorks Biochemical Oxygen Detail Data |
| cb3 | CliBench Mk III Data |
| cb4 | Actuate Analytics Cube Data |
| cba | DB/TextWorks SQL Textbase Definition |
| cbb | DB/TextWorks SQL Textbase Structure Definition |
| cbg | CyberGauge Data File |
| cbin | CACTVS Binary File |
| cbk | DYMO CardScan Backup Data |
| cbml | Vernier Logger Pro 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 |
| cc | STK City Database Counties |
| cc3 | CUEcards Data |
| cc4 | Crossword Compiler v4 Crossword Data |
| cca | cc:Mail Archive |
| ccc | Microsoft Comic Chat Conversation Data |
| cce | Cumulus 6 Category Export Data |
| ccf | Cryptload Container Format File |
| cch | .NET Security Cache |
| ccj | Compiled Crossword Applet |
| ccj | Corticon Server Rulesets Data |
| cck | COMcheck Data |
