As a member of the "Better Than Best" 91st Company, Gallagher's Griffyns, Infantry Officer Class 42-67, Fort Benning, Georgia, 5 Feb 67-21 Jul 67, I recall attending a block of instruction in Infantry Hall (Building 4) that treated the coordination and cooperation of Army and Marine infantry units while engaged in joint combat operations. The instructor was a little known Marine Lieutenant Colonel named Paul X. Kelley. LTC P. X. Kelley went on to become the youngest Marine to be promoted to the rank of General and, eventually, served as the 28th Commandant of the Marine Corps and Member of the Joint Chiefs of Staff from 1983 until his retirement in 1987 after 37 years of service.