The simple Dicta Boelcke manual has, over time, evolved into widespread use of tactics, techniques, and procedures manuals for air forces worldwide. The United States Joint Chiefs of Staff (JCS), the United States Navy (USN), and the United States Air Force (USAF) each have their own air tactics manuals. Under the auspices of the North Atlantic Treaty Organization (NATO), the USAF trains German, Dutch, Norwegian, Turkish, Italian, and Greek fighter pilots at Sheppard Air Force Base, using air tactics manuals descended from the Dicta Boelcke.[5][15]