Overprint on official stamps in order to convert them into regular postage stamps: "private" over the word "official", "0" over the symbol "No.", a line obliterating the name and number of the district (school), and a new denomination of 1 kopek. Print run: 225 copies.
Official stamps were intended for official correspondence sent via the Zemstvo post. Used in 1912β1914; issued free of charge, but accounted for. Blue ones were for 10 medical districts.