Overprint on official stamps to reclassify them as regular postage stamps: "private" over the word "official", "0" over the "No." symbol, a line obliterating the district (school) name and number, and a new denomination of 1 kopek. Print run: 10 copies.
Official stamps were intended for official correspondence sent via the Zemstvo post. Used in 1912β1914, issued free of charge but accounted for. Blue stamps were for ten medical districts.