| cfs | Compact File Set |
| cgdb | Microsoft Office Clip Art Package |
| chc | GFI MailEssentials Patch |
| chksplit | Incredible Bee Archiver Split Checksum |
| chz | ChArc Compressed Archive |
| ci3 | Crimson 3 Image |
| cig | Fastback Plus Compressed Backup |
| cjl | DigitalHIWAY Concatenated JPEG Library |
| cl2arc | Comic Life 2 Document Archive |
| cmp | Microsoft SharePoint Content Migration Package |
| cmpack | Aptify CM Tool Package |
| cnr | CNR Installation Package |
| cod | BlackBerry COD Archive |
| colpkg | Anki Fashcard Collection Package |
| costylepack | Capture One Style Package |
| cp9 | ChoicePoint Encrypted |
| cpack | Cpack Archive |
| cpct | Compact Pro Archive |
| cpgs | cPGS Addon Package |
| cpgz | Gzip Compressed CPIO Archive |
| cpio | CPIO Archive |
| cru | Crush Compressed Archive |
| crx | Chrome Extension |
| cryptomite | CryptoMite Encrypted Archive |
| ctw | CTW Compressed File |
| ctz | Custody Toolbox Compressed Backup |
| cwu | Across crossWAN Package |
| cxarchive | CrossOver Bottle Archive |
| czar | Cherwell Archive Repository |
| czip | ZIPGenius CryptoZip Archive |
