By the start of the Second World War in 1939, the SS had effectively gained complete operational control over the German Police, although outwardly the SS and Police still functioned as separate entities. The Ordnungspolizei maintained its own system of insignia and Orpo ranks as well as distinctive police uniforms. Under an SS directive known as the "Rank Parity Decree", policemen were highly encouraged to join the SS and, for those who did so, a special police insignia known as the SS Membership Runes for Order Police was worn on the breast pocket of the police uniform.