To regulate the volume of airmail to and from the armed forces stationed on the Eastern front and in Scandinavia. Greece, and Africa, concession labels or stamps were introduced. All airmail from Germany was sent to the newly created Luftpost Sammelstelle (airmail central depot) in Berlin, which sorted and directed it. All eligible members of the armed forces were issued a small quantity of these concessions stamps for both their own airmail to Germany and their reply airmail from Germany. The maximum weight was ten grams. The quantities issued varied according to different times and localities, and available transport. Initially, one stamp per card or letter was required, and each soldier received four labels per month. After April 1943. two labels were necessary for a letter and one for a card, and the quantity was increased to eight labels per month. Labels were sent in the letters home, as they were required to be affixed to mail from Germany to soldiers in the field. This post was free of charge both ways.