| comment | Geomview Comment Object Data |
| comparison7 | Araxis Merge Comparison Data |
| complete | SendSafe Deciphered E-message Data |
| compo | DAZ 3D Carrara Pro Temporary Data |
| con | Acharya Consonant Data |
| con | ALEID2000 Contour Data |
| con | BI/Query Connection File |
| con | Cimagraphi Trace Data |
| con | Corel WordPerfect Concordance Data |
| con | KJT-200 Constituent Data |
| con | MySQL SQL Constraints Script |
| con | Petrosys Contour Data |
| con | PTC Creo Connector Parameters Data |
| con | SQL Script Constraints |
| con | USoft Conceptual Schema Data |
| conf-auto | WOW! Diagnostic Configuration Data |
| conffiles | Debian Package Configuration Files Data |
| conform | Conformalizer Change List |
| conl | PJM CONL Data |
| conp | SynTest Design Connectivity Information |
| consis | Sciral Consistency Document |
| cont | Panasonic Camcorder Metadata |
| contact | Windows Vista Contacts Data |
| contacts | Windows Vista Contacts Data |
| contree | IQ-TREE Consensus Tree Data |
| control | HEC-HMS Control Specifications Data |
| coo | Autodesk AutoCAD Bounding Coordinates Cookie |
| coo | Tajima Embroidery Data File |
| cook | Netscape for Mac Cookie Data |
| cookie | HTTP Cookie Data |
| cool | QB - Text Analyzer Vocabulary Data |
| coords | Ribbons Coords Data |
| cor | CYANA DG Cartesian Coordinate File |
| cor | Insight II Output Coordinate Data |
| cor1 | Corel Multimedia Manager Data |
