Possible Clues:

• USMC enlistees
• Low mil. ranks
• USMC ranks
• Low-ranking GIs
• Ryan and Benjamin: Abbr.
• U.S.M.C. recruits: Abbr.
• Most G.I.'s: Abbr.
• Recruits, for short
• Beetle and Gomer: abbr.
• A lot of mil. personnel