| cryptra | Cryptra One Time Pad Encrypted File |
| crz | Poser Compressed Character |
| cs | ClearSilver Template File |
| cs | Adobe Encore Color Set |
| cs3 | Casio WK-1800 Song Sequencer Data |
| csa | Cadstar Schematic Design |
| csaplan | SPSS Complex Sample Analysis Plan |
| csb | Corel Binary Script |
| csc | Corel Script |
| csc | STK Calculation Scalar File |
| csc | CHARTrunner Control Chart Style |
| cscpflt | Colasoft Capsa Project Filter Data |
| cscpro | Colasoft Capsa Protocol Data |
| cscta | Colasoft Capsa Time Analyze Data |
| csdate | ClickStamper Date Stamp Data |
| csdb | CSPro Database |
| csdf | SPICE Common Simulation Data Format File |
| csdsig | Altaro Oops!Backup Data |
| csfdb | Open CASCADE 3D Model |
| csgen | ClickStamper Data |
| csh | CHARTrunner Histogram Style |
| csj | BlackBerry Code Signing Data |
| csk | BlackBerry Code Signing Keys |
| csm | Mail.dat Container Summary File |
| csn | Race Studio 2 Custom Sensors Data |
| cson | CoffeeScript Object Notation |
| csp | CHARTrunner Pareto Style |
| csplan | SPSS Sampling Plan |
| csstore | iOS Cache Data |
| cssx | Now Platform External CSS |
| cst | ClearSilver Template File |
| cst | CHARTrunner Control Chart Style |
| csutil | ColorSync Utility Data |
| csvx | uProduce Server CSVX Data |
| csy | ACDSee Canvas Symbol Data |
