Specialist
From Halopedia, the Halo wiki
Template:Ratings Template:Rank Infobox Specialist is the fourth progressive enlisted rank in the UNSC Army and is the highest enlisted rank. It is equal in rank to Petty Officer Third Class in the UNSC Navy, and Corporal in the UNSC Marine Corps
The rank of Specialist is equal to that of a Corporal in the Army or Marine Corps.
