Lieutenant colonel
From Halopedia, the Halo wiki
Template:FactOrFiction Template:Rank Infobox N.B.: This rank has not yet been mentioned in the Halo Universe.
Lieutenant Colonel is a commissioned officer rank of the UNSC Marine Corps, equal in rank to Commander in the UNSC Navy.
A Lieutenant Cololnel typically commands a Battalion-sized unit (300 to 1,000 soldiers), with a Sergeant Major as senior non-commissioned officer. A Lieutenant Colonel may also serve as a Brigade or task force Executive Officer (second in command).
