Bahnpost

Railway postmark: Bahnpoststempel (Ger.) ; Oblitération de Chemin d'Fer (Fr.) ; Bollo di Ferrovia (It.) ; Matasellos de Ferrocarril (Sp.) Railway post office (RPO): post office in a mail car on board a railroad, many often have a route marking.

Bahnpost - Railway
Btonn - Paper watermarked with straight parallel lines.
Bicoloured - Two coloured; usually refers to a stamp.
Bilingual - Postage stamp printed in two languages.

Other postmarks indicate railway post office handling with the words "Ambulante" (French or Spanish), "Tren" (Spanish) and "Bahnpost" (German).

See also: Ambulant, Catalog, Used, Type, Gauge