40 Commando RM is a battalion sized formation of the British Royal Marines and subordinate unit within 3 Commando Brigade, the principal Commando formation, under the Operational Command of Commander in Chief Fleet. All personnel will have completed the Commando course at the Commando Training Centre(CTCRM) at Lympstone in Devon, entitling them to wear the green beret, with attached personnel having completed the All Arms Commando Course.