Canon EOS-1D Mark IV - Manual (Page 173)

• Protecting Images
S
If you format the card (p.50), the protected images will also be erased.
To protect an image, press and quickly let go of the button. If you
hold down the button for approx, 2 sec., a voice memo will be recorded.
Images can also be protected Individually when the [El' Protect Images]
menu option is set to [Select images]. Press <@> to protect or
unprotect the Image.
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.179), only the protected Images will
remain. This Is convenient when you want to erase unnecessary Images
all at once.
If [.f?. C.Fn IV -9: button function] Is set to [1 : Record memo
(Protect: Disabled)] or [2: Play memo (hold: Record memo)]. Images
cannot be protected with the button. Use the [D‘ Protect
images] menu option's [Select images] to protect Images.
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