Unconfirmed issue.
A local issue of 1920, caused by the revaluation of stamps in circulation at a ratio of 1:100: handstamps of various types in black ink with the letter "R" or the word "RUB", as well as a handwritten inscription in light violet ink with the letter "R" on Russian postage stamps of 1, 2, 3, 4, 5, 10, 10/7, 15, and 20 kopeks.
Kostanay is a city located on the Tobol River in northern Kazakhstan. Until 1895 it was known as Nikolaevsk, and then as Kustanay until 1997.
A significant number of provisionals is associated with the Civil War of 1918β1922. At that time, stable central authority was absent across most of the country, many regions became independent, and, amid devastation and war, there was considerable inflation. Frequent tariff changes and the inability to supply the postal network with stamps of the required denominations led to periodic revaluations of existing stocks in accordance with instructions from the People's Commissariat of Posts and Telegraphs of the RSFSR, which did not ΠΏΡΠ΅Π΄ΡΡΠΌΠ°ΡΡΠΈΠ²Π°Π»ΠΈ any overprints. However, locally, some post offices still applied overprints to the revalued stamps offered for sale, or simply wrote on them by hand. All these stamps are characterized by extremely simple overprint techniques.