Admission stamps are stamp like prints without face value. With this stamps a sender of a shipment can get the admission for useing a privileged
or limited postal service. This are no postage stamps.
Parcel Admission Stamp: for parcels from or to (West-)Berlin for the case of a second blockade
Air Fieldpost Admission Stamp: for military covers with air mail during World War II
Air Mail Admission Stamp: for commercial covers with air mail from Germany to foreign countries between 01.05. - 19.10.1948