Canon EOS-1 D X Mark II Instruction Manual page 416

W Digital Print Order Format (DPOF)
All image
Note that RAW images and movies will not be included in the print order
even if you set [By n] or [All image].
416
If you select [Mark all on card], one
copy of all the images on the card will be
set for printing.
If you select [Clear all on card], the print
order will be cleared for all the images on
the card.