Canon POWERSHOT SD400 DIGITAL ELPH User Manual page 134

You can erase all the images saved on the SD card.
_, Please note that erased images cannot be recovered. Exercise
adequate caution before erasing an image.
® Protected images cannot be erased with this function.
®
@
in the [] (Play) menu,select
andpressthe FUNC./SET button.
See Selecting Menus and Settings (p. 48).
Use the ÷ or ,_ button to select
[OK]andpressthe FUNC./SET
button.
To exit instead of erasing, select [Cancel].
You should format the SD card when you want to erase not only image
data but also all the data contained on the card (p. 25).
132