Canon RebelT3I EOS 600D Instruction Manual page 24

[] Protecting Images
ProtectingAll Imagesin a FolderOrCard
You can protect all the images in a folder or card at one time,
When you select [All images in folder]
or [All images on card] in [;]" Protect
images], all the images irmthe folder or
card will be protected,
To carmcel the image protection, select
[Unprotect all images in folder] or
[Unprotect all images on card].
if you format the card (p.45), 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.225), only the protected images will
remain. This is convenient when you want to erase unnecessary images
all at once.
223