Luftpost

Mit Luftpost: By Air, inscription on Colombia, Switzerland etiquettes, many other nations.
Mittellitauen: (Ger.) Central Lithuania.
Mittelstück: (Ger.) center piece (single stamp, multiple or block) in a sheet or large block of stamps.

Stamps from other nations use other words to identify their stamps, such as "Aereo" from Spanish-speaking lands, "Flugpost" or "Luftpost" from Germany, "Poste Aerienne" from France, and so on.

Local - A postage stamp authorised for use only within a limited territory.
Luftpost - (German) Airmail.

See also: Catalog, Used, Official, Denomination, Airmail