It's called a "T-Card" setting.
It is a setting to "restore" the base firmware. You load the correct file in a folder called "image" on the sdcard, run that setting, and when the phone reboots itself, it restores the phone to "factory condition"
Unfortunately, we cannot find a "T-Card" image for the Merit.
Works GREAT on the Avail (returns it to a "factory stock" phone.)
DO NOT USE THE AVAIL T-CARD IMAGE ON THE MERIT!!!