British army postal service free of charge official letter (notation On His Majestys Service) of the deputizing director of the railway transportation industry (D. A. D. R. T. ) to a member the so-called Nollet mission ( = Interalliierte Military control commission under the chair of the French General Charles Nollet) in Berlin, ZKr ARMY post OFFICE A 8 JU 21 S. 120 (OS handbook number 2.1.2), furthermore violet official stamp three lines frame cancel D (EPUTY) A (SSISTANT) D (IRECTOR OF) R (AILWAY) T (RANSPORTS) / UPPER SILESIA / 8 JUN1921 (OS handbook number BDd) and red single circle signal / -9. June 1921 / control (in the OS handbook unlisted), covers and postcards of the British Unit in Upper Silesia, the whose field post office S120 mailed were, are very rare, according to OS handbook are up to now only 10 such documents are known, the here offered letter is on this list unlisted, furthermore was he the eldest known document of the British troop contingent in Upper Silesia with the fieldpost cancel S. 120, transport traces