| Extension | File Description |
| .CRAW | Uncommon Files |
| .CRAZE | Uncommon Files |
| .CRAZY | Uncommon Files |
| .CRB | Uncommon Files |
| .CRC16 | Uncommon Files |
| .CRDEL | Uncommon Files |
| .CRE | Uncommon Files |
| .CREATOR | Uncommon Files |
| .CREDITS | Uncommon Files |
| .CREG | Uncommon Files |
| .CRG | Uncommon Files |
| .CRH | Uncommon Files |
| .CRI | Uncommon Files |
| .CRJ | Uncommon Files |
| .CRK | Uncommon Files |
| .CRLD | Uncommon Files |
| .CRM | Uncommon Files |
| .CRN | Uncommon Files |
| .CRO | Uncommon Files |
| .CRONTAB | Uncommon Files |
| .CROPS | Uncommon Files |
| .CROSS | Uncommon Files |
| .CROWN | Uncommon Files |
| .CRP | Uncommon Files |
| .CRQ | Uncommon Files |
| .CRR | Uncommon Files |
| .CRU | Uncommon Files |
| .CRUNCH | Uncommon Files |
| .CRUNCHER | Uncommon Files |
| .CRYPTOMITE | Uncommon Files |
| .CRYPTX | Uncommon Files |
| .CRYSTALHAM | Uncommon Files |
| .CS-CNF | Uncommon Files |
| .CS0 | Uncommon Files |
| .CS1 | Uncommon Files |
| .CS2 | Uncommon Files |
| .CS3 | Uncommon Files |
| .CS4 | Uncommon Files |
| .CS5 | Uncommon Files |
| .CS6 | Uncommon Files |
| .CS7 | Uncommon Files |
| .CS8 | Uncommon Files |
| .CS9 | Uncommon Files |
| .CSB | Uncommon Files |
| .CSC | Uncommon Files |
| .CSE | Uncommon Files |
| .CSFDB | Uncommon Files |
| .CSG | Uncommon Files |
| .CSHRC | Uncommon Files |
| .CSJ | Uncommon Files |
| .CSK | Uncommon Files |
| .CSLM | Uncommon Files |
| .CSML | Uncommon Files |
| .CSQ | Uncommon Files |
| .CSS1 | Uncommon Files |
| .CSU | Uncommon Files |
| .CSUP | Uncommon Files |
| .CSVENX | Uncommon Files |
| .CSW | Uncommon Files |
| .CSX | Uncommon Files |
| .CSZ | Uncommon Files |
| .CS_ | Uncommon Files |
| .CT0 | Uncommon Files |
| .CT1 | Uncommon Files |
| .CT2 | Uncommon Files |
| .CT3 | Uncommon Files |
| .CT4 | Uncommon Files |
| .CT5 | Uncommon Files |
| .CT6 | Uncommon Files |
| .CT7 | Uncommon Files |
| .CT8 | Uncommon Files |
| .CT9 | Uncommon Files |
| .CTA | Uncommon Files |
| .CTAB | Uncommon Files |
| .CTC | Uncommon Files |
| Extension | File Description |
| .CTD | Uncommon Files |
| .CTE | Uncommon Files |
| .CTFSYS | Uncommon Files |
| .CTH | Uncommon Files |
| .CTI | Uncommon Files |
| .CTJ | Uncommon Files |
| .CTK | Uncommon Files |
| .CTN | Uncommon Files |
| .CTO | Uncommon Files |
| .CTQ | Uncommon Files |
| .CTR | Uncommon Files |
| .CTRL | Uncommon Files |
| .CTS | Uncommon Files |
| .CTU | Uncommon Files |
| .CTW | Uncommon Files |
| .CTZ | Uncommon Files |
| .CU0 | Uncommon Files |
| .CU1 | Uncommon Files |
| .CU2 | Uncommon Files |
| .CU3 | Uncommon Files |
| .CU4 | Uncommon Files |
| .CU5 | Uncommon Files |
| .CU6 | Uncommon Files |
| .CU7 | Uncommon Files |
| .CU8 | Uncommon Files |
| .CU9 | Uncommon Files |
| .CUA | Uncommon Files |
| .CUBE | Uncommon Files |
| .CUBI | Uncommon Files |
| .CUC | Uncommon Files |
| .CUD | Uncommon Files |
| .CUF | Uncommon Files |
| .CUG | Uncommon Files |
| .CUH | Uncommon Files |
| .CUI | Uncommon Files |
| .CUJ | Uncommon Files |
| .CUK | Uncommon Files |
| .CUM | Uncommon Files |
| .CUN | Uncommon Files |
| .CUO | Uncommon Files |
| .CUP | Uncommon Files |
| .CUQ | Uncommon Files |
| .CUREXSCHEM | Uncommon Files |
| .CURL | Uncommon Files |
| .CURSOR | Uncommon Files |
| .CURV | Uncommon Files |
| .CURVE | Uncommon Files |
| .CUSTOM | Uncommon Files |
| .CUTLIST | Uncommon Files |
| .CUU | Uncommon Files |
| .CUV | Uncommon Files |
| .CUW | Uncommon Files |
| .CUX | Uncommon Files |
| .CUY | Uncommon Files |
| .CUZ | Uncommon Files |
| .CU_ | Uncommon Files |
| .CV | Uncommon Files |
| .CV0 | Uncommon Files |
| .CV1 | Uncommon Files |
| .CV2 | Uncommon Files |
| .CV3 | Uncommon Files |
| .CV4 | Uncommon Files |
| .CV6 | Uncommon Files |
| .CV7 | Uncommon Files |
| .CV8 | Uncommon Files |
| .CV9 | Uncommon Files |
| .CVB | Uncommon Files |
| .CVC | Uncommon Files |
| .CVE | Uncommon Files |
| .CVH | Uncommon Files |
| .CVI | Uncommon Files |
| .CVIP | Uncommon Files |
| .CVJ | Uncommon Files |
| .CVK | Uncommon Files |
| .CVL | Uncommon Files |
