UNSC rank structure/Spartan

All table information sourced from Halo: Official Spartan Field Manual pages 32-33, except where otherwise noted.

Role	Spartan	Fireteam Leader	Mission Handler	Spartan Commander	Director of Spartan Operations
Responsibilities	Augmented special forces equipped with MJOLNIR Powered Assault Armor.	Field leader of a fireteam of 4-5 Spartans.	Spartan Command liaison and intelligence support stationed at headquarters. Responsible for managing 5-10 fireteams, or 20-50 Spartans.	Overall command-and-control of Spartan Company. Responsible for upwards of 300 Spartans.	Commander-in-Chief of the Spartans (CINCSPAR)
UNSC authority	First Lieutenant	Captain	Major	Colonel	General