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The ranks and insignia of the Ordnungspolizei were developed in 1936 after the nationalisation of Germany's regular police forces.
Ordnungspolizei
Ordnungspolizei (Orpo) ranks were based on local police titles and were considered a separate system from the ranks of the SS. If a member of the Order Police was already an SS member or - upon application - became an SS member, he was automatically awarded an SS rank according to his police rank. Within the police administration, only the police rank was used. In the SS environment, the equivalent SS title was usually mentioned first, even if the bearer usually had no function in the SS administration. In 1944, all Orpo generals also gained equivalent Waffen-SS ranks so that, in the event of capture by the Allies, the Orpo general would hold status as a military officer instead of a police official.
It was not until the decree of 16.4.1940 that the Order Police were allowed to show their SS affiliation in their uniforms: A small SS rune was sewn on below the left breast pocket.
Ordnungspolizei rank insignia
In addition to collar and shoulder insignia, Ordnungspolizei also wore the wreathed police eagle on the upper left sleeve. The collar patch and shoulderboards were backed, and the sleeve eagle (below the rank of Leutnant) embroidered, in truppenfarbe, a colour-code which indicated the branch of police: green for Schutzpolizei (protection police) and police general officers, wine-red for Gemeindepolizei (municipal protection police), orange for rural Gendarmerie, carmine-red for fire brigades, gold for maritime police, and light grey for administrative police.
Note: Since most police generals, increasingly as time went on, were also SS generals, they typically wore an SS uniform except at police-specific functions.