| Extension | File Description |
| .CL9 | Uncommon Files |
| .CLA | Uncommon Files |
| .CLAP | Uncommon Files |
| .CLBX | Uncommon Files |
| .CLC | Uncommon Files |
| .CLDLYR | Uncommon Files |
| .CLE | Uncommon Files |
| .CLEAN | Uncommon Files |
| .CLEANER | Uncommon Files |
| .CLEAR | Uncommon Files |
| .CLEARANCE | Uncommon Files |
| .CLF | Uncommon Files |
| .CLH | Uncommon Files |
| .CLI | Uncommon Files |
| .CLICK | Uncommon Files |
| .CLIP | Uncommon Files |
| .CLIP1 | Uncommon Files |
| .CLIP2 | Uncommon Files |
| .CLJ | Uncommon Files |
| .CLL | Uncommon Files |
| .CLMOV | Uncommon Files |
| .CLN | Uncommon Files |
| .CLO | Uncommon Files |
| .CLOCK | Uncommon Files |
| .CLOE | Uncommon Files |
| .CLOG | Uncommon Files |
| .CLOSED | Uncommon Files |
| .CLOUD | Uncommon Files |
| .CLQ | Uncommon Files |
| .CLU | Uncommon Files |
| .CLUB | Uncommon Files |
| .CLUBS | Uncommon Files |
| .CLV | Uncommon Files |
| .CLY | Uncommon Files |
| .CLZ | Uncommon Files |
| .CL_ | Uncommon Files |
| .CM0 | Uncommon Files |
| .CM1 | Uncommon Files |
| .CM3 | Uncommon Files |
| .CM4 | Uncommon Files |
| .CM5 | Uncommon Files |
| .CM6 | Uncommon Files |
| .CM7 | Uncommon Files |
| .CM8 | Uncommon Files |
| .CM9 | Uncommon Files |
| .CMA | Uncommon Files |
| .CMB | Uncommon Files |
| .CMBX | Uncommon Files |
| .CMC | Uncommon Files |
| .CMD5 | Uncommon Files |
| .CMDF | Uncommon Files |
| .CMDR | Uncommon Files |
| .CMG | Uncommon Files |
| .CMH | Uncommon Files |
| .CMI | Uncommon Files |
| .CMJ | Uncommon Files |
| .CMK | Uncommon Files |
| .CMMF | Uncommon Files |
| .CMN | Uncommon Files |
| .CMO | Uncommon Files |
| .CMPRB | Uncommon Files |
| .CMPT | Uncommon Files |
| .CMQ | Uncommon Files |
| .CMR | Uncommon Files |
| .CMRBK | Uncommon Files |
| .CMRT | Uncommon Files |
| .CMT | Uncommon Files |
| .CMTD | Uncommon Files |
| .CMU | Uncommon Files |
| .CMUWM | Uncommon Files |
| .CMV | Uncommon Files |
| .CMW | Uncommon Files |
| .CMXA | Uncommon Files |
| .CMY | Uncommon Files |
| .CMYK | Uncommon Files |
| Extension | File Description |
| .CMZ | Uncommon Files |
| .CN | Uncommon Files |
| .CN0 | Uncommon Files |
| .CN1 | Uncommon Files |
| .CN2 | Uncommon Files |
| .CN3 | Uncommon Files |
| .CN4 | Uncommon Files |
| .CN5 | Uncommon Files |
| .CN6 | Uncommon Files |
| .CN7 | Uncommon Files |
| .CN8 | Uncommon Files |
| .CN9 | Uncommon Files |
| .CNB | Uncommon Files |
| .CNC3REPLAY | Uncommon Files |
| .CND | Uncommon Files |
| .CNDF | Uncommon Files |
| .CNE | Uncommon Files |
| .CNG | Uncommon Files |
| .CNH | Uncommon Files |
| .CNI | Uncommon Files |
| .CNJ | Uncommon Files |
| .CNK | Uncommon Files |
| .CNL | Uncommon Files |
| .CNM | Uncommon Files |
| .CNN | Uncommon Files |
| .CNO | Uncommon Files |
| .CNP | Uncommon Files |
| .CNQ | Uncommon Files |
| .CNR | Uncommon Files |
| .CNREG | Uncommon Files |
| .CNREP | Uncommon Files |
| .CNU | Uncommon Files |
| .CNW | Uncommon Files |
| .CNX | Uncommon Files |
| .CNY | Uncommon Files |
| .CNZ | Uncommon Files |
| .CN_ | Uncommon Files |
| .CO | Uncommon Files |
| .CO$ | Uncommon Files |
| .CO0 | Uncommon Files |
| .CO1 | Uncommon Files |
| .CO2 | Uncommon Files |
| .CO3 | Uncommon Files |
| .CO4 | Uncommon Files |
| .CO5 | Uncommon Files |
| .CO6 | Uncommon Files |
| .CO7 | Uncommon Files |
| .CO8 | Uncommon Files |
| .CO9 | Uncommon Files |
| .COA | Uncommon Files |
| .COBRA | Uncommon Files |
| .COC | Uncommon Files |
| .COCO | Uncommon Files |
| .CODE | Uncommon Files |
| .CODE0 | Uncommon Files |
| .CODE1 | Uncommon Files |
| .CODE2 | Uncommon Files |
| .CODE3 | Uncommon Files |
| .CODE4 | Uncommon Files |
| .CODEC | Uncommon Files |
| .CODES | Uncommon Files |
| .COE | Uncommon Files |
| .COG | Uncommon Files |
| .COH | Uncommon Files |
| .COI | Uncommon Files |
| .COJ | Uncommon Files |
| .COK | Uncommon Files |
| .COKE | Uncommon Files |
| .COLA | Uncommon Files |
| .COLLAPSE | Uncommon Files |
| .COLLOQUYTR | Uncommon Files |
| .COLOGNELA | Uncommon Files |
| .COLOR | Uncommon Files |
| .COLOR2 | Uncommon Files |
| .COLORS | Uncommon Files |
