_Military Aviator_—Two wings with a shield between bearing the letters “U. S.” and a star above, embroidered in silver on a blue background except the letters which are in gold thread. _Junior Military Aviator and Reserve Military Aviator_—The same, omitting the star. _Military Aeronaut_—Two wings with a balloon between bearing the letters “U. S.” and a star above, embroidered in white on a blue background except the letters which are in gold. _Junior Military Aeronaut and Reserve Military Aeronaut_—The same, omitting the star. _Observer_—A letter “O” with a single wing on the left of it embroidered in white on a blue background. For enlisted men the insignia are embroidered in white on a blue sleeve cap let in at the shoulder seam and extending down the sleeve 5½ inches: _Enlisted Aviator_—Two wings with crossed propellers between them and the number of the squadron above. _Aviation Mechanician_—A circle enclosing crossed propellers with the number of the squadron above. _Other Enlisted Men_—The same, omitting the circle. [Illustration: U. S. Army. Noncommissioned officers’ chevrons 1. First Class Gunner, Mine Company 2. Second Class Gunner, Mine Company 3. First Class Private, Engineer Corps 4. First Class Private, Hospital Corps 5. Saddler, Cavalry 6. Horseshoer, Cavalry 7. Cook 8. Badge for Excellence in Target Practice, Coast Artillery] [Illustration: U. S. Army. Enlisted men’s insignia worn on dress coat collars indicating arm of the Service, Corps or Department 1. Infantry, Porto Rico Regiment 2. Infantry 3. Native Philippine Troops 4. Cavalry 5. Artillery 6. Engineer Corps 7. Hospital Corps 8. Ordnance Corps 9. Quartermaster Corps 10. Band Musician, Engineers 11. Electrician 12. Signal Corps 13. Band Musician 14. Band, Philippines 15. Band, Porto Rico] _Brassards_ are bands of cloth worn on the sleeves to designate officers and men assigned to special duties. _Red Cross Brassard._—In time of war with signatories of the Geneva Convention all persons in the military services who are rendered neutral by the terms of that convention wear upon the left arm above the elbow a brassard of white cloth bearing upon it a Geneva cross in red cloth while on duty in the field of operations. The persons entitled to wear this brassard are surgeons, members of the hospital corps, nurses, chaplains and the personnel engaged exclusively with the removal and transportation of the sick and wounded.