"Postschutz" - "Deutsche Reichspost" - Pietsch
I.D of "Postschutzmann" Albert Pietsch who served within the "Postschutz" (postal security) of the "Deutsche Reichspost"
The "Feldpost" and such was very important during WW II as it was the only way of communication between faraway front and home and was probably the best source to keep up the morality.
Rarely seen I.D.!!