Canon EOS-1D X Mark II DSLR Camera (Body Only) - Manual (Page 360)

J Protecting Images
360
You can protect all the images in a folder or on a card at once.
When you select [ All images in folder ]
or [ All images on card ] in [ 3 1:
Protect images ], all the images in the
folder or on the card will be protected.
To cancel the image protection, select
[
Unprotect all images in folder ] or
[ Unprotect all images on card ].
3 Protecting All Images in a Folder or on a Card
If you format the card (p.74) , the protected images will also be erased.
Movies can also be protected.
Once an image is protected, it cannot be erased by the camera’s erase
function. To erase a protected image, you must first cancel the
protection.
If you erase all the images (p.388), only the protected images will
remain. This is convenient when you want to erase unnecessary images
all at once.
When [ All images on card ] or [ Unprotect all images on card ] is
selected, the images will be protected or unprotected on the card
selected for [
Record/play ] or [ Playback ] under [ 5 1: Record
func+card/folder sel. ].