Chief warrant officer in the United States Armed Forces refers to any warrant officer in pay grades CW2 and above. All warrant officers (WO1 to CWO5) are officers and rate a salute by all enlisted NATO other ranks personnel. The U.S. Army and the U.S. Marine Corps use WO1/WO through CW5/CWO5 as designators and the U.S. Navy uses WO1 for one specialty (cyber warfare); all other branches of the U.S. Armed Forces use CWO2 through CWO5. The U.S. Air Force, although authorized to appoint warrant officers, does not utilize those grades in any capacity. All warrant officers dine in the officers' mess but rate just below O-1 (NATO rank code OF-1).