Canon EOS R5 C VR Creator Kit with RF 5.2mm f/2.8 Dual Fisheye Lens - Manual (Page 665)

3.
Register the desired items.
Select the Custom shooting mode to register, then select [ OK ] on the
[ Register settings ] screen.
The current camera settings are registered to Custom shooting mode
C*.
Automatic Update of Registered Settings
If you change a setting while shooting in Custom shooting mode, the mode can be
automatically updated with the new setting (Auto update). To enable this automatic update,
set [
Auto update set. ] to [ Enable ] in step 2.
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