| crd | CHARTrunner Dashboard |
| crd | MODELLER Atom Coordinates CHARMM Data |
| crdb | Carlson 2016 Coordinate Database |
| crds | Windows CardSpace Backup |
| creole | Creole Source Code |
| crf | Cal3D Binary Materials Data |
| crf | MOUSE Runoff Data |
| crf | Sierra Print Artist Craft Data |
| crg | OpenCRG Data File |
| cri | PLS-CADD Criteria |
| cri | WaterGEMS Criticality Analysis Results Data |
| crl | Certificate Revocation List |
| crld | Clicker Crick Resource Library Data |
| crm | WRAP Conditional Reliability Modeling Data |
| crmlog | Microsoft Windows COM+ CRM Log |
| cro | AquaCrop Crop Data |
| cro | CropWat Data |
| crossdb | MixVibes Cross DJ Collection Data |
| crpd | Microsoft Windows SignTool Data |
| crpt | Cryptosaurus Encrypted File |
| crq | Blackboard Course Requests |
| crr | Cgatools CRR File |
| crr | SVAL Correction Data |
| crs | CompuTrainer Chart Screen |
| crs | Corel WordPerfect Conversion Resource Data |
| crs | Document Conversion Resource |
| crs3 | OmniPage Lite Data |
| crt | Oracle Terminal Settings Information |
| crtx | Microsoft Excel 2007 Custom Chart Template |
| crv | ANSYS TurboGrid Curve File |
