| cel | Celestia CEL Script |
| cel | PTC Creo Machine Parameter Data |
| cell | CASTEP Cell Input Data |
| celx | Celestia Script File |
| cen | CEN EN 13032 Photometric Data |
| cept | Creative Element Power Tools Data |
| cer | MSI Cerius 2 Format Data |
| cer | Sierra Print Artist Certificate |
| cert | Netscape Certificate Index |
| cert | Nintendo Switch Certificate Data |
| cert | Open Virtual Machine Format Certificate |
| cetrainer | DBVM Data |
| cev | SEL Compressed Event Report |
| cex | CLAN Output Data |
| cex | SolidWorks Enterprise PDM Exported Vault Settings |
| cez | Prosurv cEZ Job File |
| cezeokey | CEZEO Product Key Data |
| cf | 1C:Enterprise Configuration Data |
| cf | CFEngine Policy Data |
| cf1 | Common Loudspeaker Format Type 1 File |
| cf1 | WOW! Diagnostic CF1 Data |
| cf10 | IRIG 106 Original Recording Data |
| cf2 | Common Loudspeaker Format Type 2 File |
| cf3 | CFEngine Database |
| cf3 | CFEngine Policy Data |
| cf4 | Catfish File Manager Support Data |
| cf5 | Docuware v5 Content Folder File |
| cf7 | Cashflow Manager v7 Data File |
| cf8 | Cashflow Manager v8 Data |
| cf9 | Cashflow Manager v9 Data |
| cfa | ComProbe Analyzer Captured Data |
| cfb | Disk Drill Recovered Data |
| cfb | Spike2 Filter Bank Data |
| cfbx | Spike2 v7 Filter Bank Data |
| cfd | CryptoForge Document |
