NSDAP Armband, Head Department Leader

The "armband system" was instituted by the Nazi Party in 1939 at the same time that the political leadership ranks were expanded into their final form. The purpose of the armband system was to denote positional titles within the Nazi Party in contrast to a party member's political rank.[1]

There were three groupings of armbands, classified as "operational", "administrative", and "command". The operational armbands were used by Nazi Party political leaders on the local and county levels and were worn by those Party leaders directly engaged in implementing Party policies to the public. During World War II, this was most often associated with food rationing, war relief efforts, and civil defence.

The administrative armbands were worn by office staffs across all levels of the party, although mostly were used by the regional staffs of the Gauleiters. The third, and least common of the armbands, were the command armbands worn by the Deputy Gauleiters, Gauleiters, and Reichsleiters.

The Nazi Party armbands were intended for immediate implementation upon the outbreak of World War II in 1939, although it was not until 1943 that the system was in total effect. Even then, photographic evidence reveals it was not uncommon for some political leaders to simply wear the pre-1939 bare swastika armband, with some photographs as late as 1945 revealing political leaders failing to wear the appropriate Nazi positional armband.

Source : Wikipedia, Ranks and insignia of the NSDAP Party