See the "Related Information" in below ”Product Information" > "Setting Menu List".
Locked menus are marked with 
. Lower level menus will also be locked.
Besides the Settings menu, Lock Setting applied to the following items in the Presets menu.
Add New
(Delete)
Sort
Add Shortcut on Home Screen
Depending on the printer model and firmware version, the network icon and the Run Connection Check menu on the Help screen may also be configurable with Lock Setting.