Canon EOS-1D X Mark III DSLR Camera (Body Only) - Manual (Page 783)

6.
Exit the setting.
When finished, press the < > button to return to the screen in
step 2.
7.
Review your setting screen.
Sample screen
Confirm that [ Custom Quick Control screen ] in [ : button
display options ] has a checkmark [ ] ( ).
Press the < > button to display the Custom Quick Control screen
( ), then check the layout.
783