Type 3: reduced "Y".
Overprint on official stamps in order to convert them into regular postage stamps: "private" over the word "official", "0" over the "No." sign, a line obscuring the name and number of the district (school), and a new denomination of 1 kopek. Print run: 5 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.