.MRK File Extension
File TypeDPOF Auto Print Order File
What is an MRK file?
Text file saved on digital cameras along with the digital images; describes the order the pictures should be printed in when printing pictures directly from the camera; used by digital photo printing services that support the Digital Print Order Format (DPOF).
The Print Order file is usually saved in the /MISC folder on digital camera media and is named "AUTPRINT.MRK."