Rare/Genuine WW2 German Feldpost Envelope

Rare/Genuine WW2 German Feldpost Envelope (1943) with Eagle/Swastika stamp, all in very good condition Feldpost is the German military free mail service bringing letters and postcards from German soldiers on the front back to their families at home To preserve the secrecy of troop movements, each battalion was assigned a five digit code number called Feldpost number (FPN). By the end of 1939, letter prefixes "L" and "M" were attached in front of each FPN to units belonging to the Luftwaffe and Kriegsmarine. A breakdown by military units was added by attaching letter prefixes "A" through "E" at the end of each FPN. The letter A generally signified headquarters company, the others stood for line companies.