Canon Xsi Instruction Manual page 159

If the [Live View shoot.] menu has been set to [Enable], the Live View
shooting will override any setting from 1 to 4. When the camera is ready to
shoot, pressing <0> will show the Live View image instead.
C.Fn-12
0: Display
When the power switch is turned on, the shooting settings will be
displayed.
1: Retain power OFF status
If you pressed the <B> button to turn off the LCD monitor and then
you turn off the power, the LCD monitor will not turn on when you turn on
the power again. This helps to save battery power. The menu screens
and image playback will still be displayed when used.
If you pressed the <B> button and then turn off the power while the
shooting settings are displayed, the LCD monitor will turn on the next
time you turn on the power.
C.Fn-13
0: Off
1: On
Data for verifying whether the image is original or not is appended to the
image automatically. When the shooting information of an image
appended with the verification data is displayed (p.131), the <L> icon
will appear.
To verify whether the image is original, the Original Data Security Kit
OSK-E3 (sold separately) is required.
The images are not compatible with the image encryption/decryption
features of Original Data Security Kit OSK-E3.
LCD display when power ON
Add original decision data
3 Custom Function SettingsN
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