1919VELKÝ MONOGRAM WITHOUT HODNOTY-10- overprint "Czechoslovakia" on/for Hungarian PC 10 Filler red, uprated with stamp Hradčany 5h, CDS POZSONY 919 Aug.6., Us and sent to Postal headquarters in Bratislava, (according to Specializované handbooks 1988 known only 3 pcs of, see page. 398), very rare usage