Valuev Circular
The Valuev Circular (; ) of 18 July 1863 was a secret decree (ukaz) of the Minister of Internal Affairs of the Russian Empire Pyotr Valuev (Valuyev) by which a large portion of the publications (religious, educational, and literature recommended for the use in primary literacy training of the commoners) in the Ukrainian language was forbidden, with the belles lettres works. 

The Circular has put the reason for the growing number of textbooks in Ukrainian, and beginner-level books in Ukrainian with "the Poles' political interests" and the "separatist intentions of some of the Little Russians". The Circular quoted the opinion of the Kiev Censorship Committee that "a separate Little Russian language never existed, doesn't exist, and couldn't exist, and their [Little Russians]  tongue used by commoners  is nothing but Russian corrupted by the influence of Poland".

The Circular ordered the Censorship Committees to ban the publication of religious texts, educational texts, and beginner-level books in Ukrainian, but permitted publication of belles-lettres works in that language.

Further restrictions were placed on the Ukrainian language by the Ems Ukaz in 1876, which completely prohibited the usage of the language in open print.