Canon EOS R5 C VR Creator Kit with RF 5.2mm f/2.8 Dual Fisheye Lens - Manual (Page 711)

C.Fn5
Clear all Custom Func. (C.Fn)
Selecting [ : Clear all Custom Func. (C.Fn) ] clears all Custom Function settings except
[ Customize buttons ] and [ Customize dials ].
Note
Performing [ : Clear all Custom Func. (C.Fn) ] does not clear settings
configured in [ : Customize buttons ] and [ : Customize dials ]. To clear the
settings, select [ : Clear customized settings ]. Note that although information
added using [ : Add IPTC information ] is retained, the setting changes to
[ Disable ].
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