... used for control, signals, reverse function in CNC machine tools, shipbuilding, textiles, printing, electrical and other ... code(as table) Code namemeansCode namemeansGeneral buttonXRole button*General symbol buttonsXBRotary buttonDWith light buttonXDWith light knobZSelf ... lock level buttonMMushroom buttonZPDSelf-locking type flat button with light buttonZMSelf lock mushroom buttonMJMushroom rush ...