[2] Currently, U.S. Army organizational doctrine uses the classification "Maneuver, Fires and Effects" (MFE) and "Operations Support" (OS) to group the former combat support arms branches into Maneuver Support; Special Operations Forces; Network and Space Operations; and Intelligence, Surveillance, and Reconnaissance functional areas.
[5] United States Marine Corps doctrine designates all Ground Combat Element (GCE) forces, other than infantry, including field artillery, assault amphibian, combat engineer, light armored reconnaissance, reconnaissance, and tanks (prior to the USMC divestiture of all tanks by the end of 2021) as combat support.
The Marine Corps also maintains a battalion-sized Chemical Biological Incident Response Force (CBIRF) as an element of the II Marine Expeditionary Force (II MEF), responsible for fulfilling the mission of Chemical, Biological, Radiological, Nuclear, and High-Yield Explosive (CBRNE) consequence management.
USMC military intelligence (intelligence battalions), military police (law enforcement battalions), and signal (communications battalions), as well as radio battalions (signals intelligence and electronic warfare), air naval gunfire liaison, force reconnaissance, psychological operations, civil affairs, and public affairs units are designated as Command Element (CE) (C4ISTAREW) units and are classed separately from GCE combat support units.
(The remaining three functions of Marine Aviation are: offensive air support, antiair warfare, and control of aircraft and missiles.)