| crv | ANSYS TurboGrid Curve File |
| crw | CHARTrunner Workspace |
| crwl | Windows Search Crawl Data |
| crypt | WhatsApp Stored Messages |
| crypt10 | WhatsApp Stored Messages |
| crypt11 | WhatsApp Stored Messages |
| crypt12 | WhatsApp Stored Messages |
| crypt5 | WhatsApp Stored Messages |
| crypt6 | WhatsApp Stored Messages |
| crypt7 | WhatsApp Stored Messages |
| crypt8 | WhatsApp Stored Messages |
| crypt9 | WhatsApp Stored Messages |
| cryptra | Cryptra One Time Pad Encrypted File |
| crz | Poser Compressed Character |
| cs | Adobe Encore Color Set |
| cs | ClearSilver Template File |
| cs3 | Casio WK-1800 Song Sequencer Data |
| csa | Cadstar Schematic Design |
| csaplan | SPSS Complex Sample Analysis Plan |
| csar | CARIS Spatial Archive |
| csb | Corel Binary Script |
| csc | Corel Script |
| csc | STK Calculation Scalar File |
| csc | CHARTrunner Control Chart Style |
| cscft | Colasoft Capsa Features Data |
| cscont | Colasoft Capsa Name Table |
| cscpflt | Colasoft Capsa Project Filter Data |
| cscpkt | Colasoft Capsa 5.0 Packet Data |
| cscpro | Colasoft Capsa Protocol Data |
| cscta | Colasoft Capsa Time Analyze Data |
