The mce file extension is associated with the Sony CAV-M1000ES receiver. Each file represents infrared control commands for a specific Common Source component that is not preprogrammed into the CAV-M1000ES. The mce files are normally "learned" by the CAVM1000ES using the handheld IR remote control of the Common Source equipment and the front panel of the M1000ES. To save the tedium of repeated manual programming, *.mce files can also be saved to your PC, recalled for later use, or even downloaded from the Internet.