| clu | NeuroScope Cluster Data |
| clut | Adobe Photoshop Color Table |
| clx | Ceelox SecureMail Secure Message |
| clx | IBM Rational XDE Collaboration Data |
| cly | Act! Design Layout File |
| cly | CorelDraw Custom Layout Data |
| cm | NucleoView Image Data |
| cm0013 | Samsung Smart TV Device Information |
| cm10 | CaseMap 10 Data |
| cm2 | Poser Camera Data |
| cm3 | CaseMap 3 Data |
| cm4 | CaseMap 4 Data |
| cm4 | ClipMate Data |
| cm5 | Clone Manager Molecule Data |
| cm5 | LexisNexis NoteMap Case Analysis Data |
| cm8 | CaseMap 8 Data |
| cma | Camomile Library |
| cma | Coach Activity File |
| cma | Filetopia Collection Manager Data |
| cmac | CICS CMAC Messages Data Set |
| cmap | CmapTools Concept Map |
| cmap | Hex Workshop Color Map |
| cmautosave | CET Designer Drawing Autosave |
| cmax | CMax Circuit Data |
| cmb | Chromeleon Backup Archive |
| cmb | QIP Infium Contact List Backup Data |
| cmb | Reason Combinator Instrument Patch |
| cmb | SGI Scalable Graphics Compositor Combination File |
| cmb | XTree for Windows Button Bar Data |
| cmbak | CET Designer Drawing Backup |
