Canon EOS-1D X Mark III Advanced User's Manual page 84

< >: Multi-Function Lock
With [ 6: Multi function lock] configured (
you can prevent the settings from being changed by accidentally touching the Main dial,
Quick control dial, Multi-controller, smart controller, or touch-screen panel.
Note
Attempting to use any locked camera controls when the power switch is set to
< > will cause <
and [
By default, the <
> to appear in the viewfinder and on the top LCD panel
] on the Quick Control screen (
> dial is locked when the power switch is set to <
) and the power switch set to <
).
84
>,
>.