Master chief petty officer

Master Chief Petty Officer is the ninth 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.

In informal settings, Master Chief Petty Officers are typically called "Master Chief"...

As shown in the ceremony for Master Chief's so called death, a silver star in place of his rate was shown which makes him a Command Master Chief