Master chief petty officer
From Halopedia, the Halo wiki
Template:Rank Infobox Master Chief Petty Officer is the ninth and highest enlisted rank of the UNSC Navy and is a non-commissioned officer. It is equal in rank to Master Gunnery Sergeant and Sergeant Major in the UNSC Marine Corps [1].
In informal settings, Master Chief Petty Officers are typically called "Master Chief" or "Chief".
