Topic summary
Officer commanding

Extracted from the Wikipedia article Commanding officer.
Army and Royal Marines
Sub-units and minor units (companies, squadrons and batteries) and formations (brigades, divisions, corps and armies) do not have a commanding officer. The officer in command of a minor unit holds the appointment of officer commanding (OC). Higher formations have a commander (e.g. brigade commander) or a general officer commanding (GOC). Area commands have a commander-in-chief (e.g. C-in-C Land Army, C-in-C British Army of the Rhine). The OC of a sub-unit or minor unit is today customarily a major (although formerly usually a captain in infantry companies and often also in cavalry squadrons), although again the rank of the appointment holder and the holder's appointment are separate and independent of each other.