The Russian orthography has been reformed officially and unofficially by changing the Russian alphabet over the course of the history of the Russian language. Several important reforms happened in the 18th-20th centuries.
Old East Slavic adopted the Cyrillic script, approximately during the 10th century and at about the same time as the introduction of Eastern Christianity into the territories inhabited by the Eastern Slavs. No distinction was drawn between the vernacular language and the liturgical, though the latter was based on South Slavic rather than Eastern Slavic norms. As the language evolved, several letters, notably the yuses (?, ?, ?, ?) were gradually and unsystematically discarded from both secular and church usage over the next centuries.
The emergence of the centralized Russian state in the 15th and 16th centuries, the consequent rise of the state bureaucracy along with the development of the common economic, political and cultural space necessitated the standardization of the language used in administrative and legal affairs. It was due to that reason that the earliest attempts at standardizing Russian, both in terms of the vocabulary and in terms of the orthography were made, initially based on the so-called Moscow chancery language. From then and on the underlying logic of language reforms in Russia reflected primarily the considerations of standardizing and streamlining language norms and rules in order to ensure the language's role as a practical tool of communication and administration.
The printed Russian alphabet began to assume its modern shape when Peter I introduced his "civil script" ( ) type reform in 1708. The reform was not specifically orthographic in nature. However, with the replacement of ? with ? and the effective elimination of several letters (?, ?, ?) and all diacritics and accents (with the exception of ?) from secular usage and the use of Arabic numerals instead of Cyrillic numerals there appeared for the first time a visual distinction between Russian and Church Slavonic writing. With the strength of the historic tradition diminishing, Russian spelling in the 18th century became rather inconsistent, both in practice and in theory, as Mikhail Lomonosov advocated a morphological orthography and Vasily Trediakovsky a phonemic one.
Throughout the 18th and 19th centuries, miscellaneous adjustments were made ad hoc, as the Russian literary language came to assume its modern and highly standardized form. These included the introduction of the letter ? (yo) and the gradual loss of ? (izhitsa, corresponding to the Greek upsilon and the Latin y), in favor of ? or ? (both of which represented /i/); and ? (corresponding to the Greek theta), in favor of ? or ?. (The Russian language neither has nor ever had a voiceless dental fricative. The ? was used only for foreign words, particularly Greek.)
By 1917, the only two words still spelled with ? were ? (müro, ['m?ir?], 'myrrh') and (sünod, [s'not], 'synod'), and rarely even at that. The ? remained more common, though it became quite rare as a "Western" (French-like) pronunciation had been adopted for many words; for example, (?eatr, [f'atr], 'theater') became (teatr, [t'atr]).
Attempts to reduce spelling inconsistency culminated in the standard textbook of Grot (1885), which retained its authority through 21 editions until the Russian Revolution of 1917. His fusion of the morphological, phonetic, and historic principles of Russian orthography remains valid to this day, though both the Russian alphabet and the writing of many individual words have been altered through a complicated but extremely consistent system of spelling rules that tell which of two vowels to use under all conditions.
Shakhmatov headed the Assembly for Considering Simplification of the Orthography whose proposals of 11 May 1917 formed the basis of the new rules soon adopted by the Ministry of Popular Education.
Russian orthography was made simpler and easier by unifying several adjectival and pronominal inflections, replacing the letters ? (Yat) with ?, ? with ?, and ? (depending on the context of Moscovian pronunciation) and ? with ?. Additionally, the archaic mute yer became obsolete, including the ? (the "hard sign") in final position following consonants (thus eliminating practically the last graphical remnant of the Old Slavonic open-syllable system). For instance, became ? ("Rybinsk").
In December 1917 the People's Commissariat of Education, headed by A. V. Lunacharsky, issued a decree stating "all state and government institutions and schools without exception should carry out the transition to the new orthography without delay... from 1 January 1918 all government and state publications, both periodical... and non-periodical" were to be printed in the new style. The decree was nearly identical to the proposals put forth by the May Assembly, and with other minor modifications formed the substance of the decree issued by the Soviet of People's Commissars in October 1918.
In this way, private publications could formally be printed using the old (or more generally, any convenient) orthography. The decree forbade the retraining of people previously trained under the old norm. A given spelling was considered a misspelling only if it violated both the old and the new norms.
However, in practice, the Soviet government rapidly set up a monopoly on print production and kept a very close eye on the fulfillment of the edict. A common practice was the removal of not just the letters ?, ?, and ? from printing offices, but also ?. Because of this, the usage of the apostrophe as a dividing sign became widespread in place of ? (e.g., ', ' instead of , ), and came to be perceived as a part of the reform (even if, from the point of view of the letter of the decree of the Council of People's Commissars, such uses were mistakes). Nonetheless, some academic printings (connected with the publication of old works and documents and printings whose typesetting began before the revolution) came out in the old orthography (except title pages and, often, prefaces) up until 1929.
Russian - and later Soviet - railroads operated locomotives with designations of "?", "?" and "?". Despite the reformed orthography, the series names remained unchanged up until these locomotives were discontinued in the 1950s.
The reform reduced the number of orthographic rules having no support in pronunciation--for example, the difference of the genders in the plural and the need to learn a long list of words which were written with "yat"s (the composition of said list was controversial among linguists, and different spelling guides contradicted one another).
The reform resulted in some economy in writing and typesetting, due to the exclusion of ? at the end of words--by the reckoning of Lev Uspensky, text in the new orthography was shorter by one-thirtieth.
The reform removed pairs of completely homophonous graphemes from the Russian alphabet (i.e., ? and ?; ? and ?; and the trio of ?, I and ?), bringing the alphabet closer to Russian's actual phonological system.
While there have not been any significant changes since the 1918 decree, debates and fluctuations have to some degree continued.
In December 1942 the use of letter ? was made mandatory by Decree No. 1825 of the People's Commissariat of Education.
A codification of the rules of Russian orthography and punctuation was published in 1956 but only a few minor orthographic changes were introduced at that time. The 1956 codification additionally included a clarification of new rules for punctuation developed during the 1930s, and which had not been mentioned in the 1918 decree.
A notable instance of renewed debate followed A.I. Efimov's 1962 publication of an article in Izvestia. The article proposed extensive reform to move closer to a phonetic representation of the language. Following the renewed discussion in papers and journals a new Orthographic Commission began work in 1962, under the Russian Language Institute of the Academy of Sciences of the USSR. The Commission published its report, ? ? (Proposal for the Improvement of Russian Orthography), in 1964. The publication resulted in widespread debate in newspapers, journals, and on radio and television, as well as over 10,000 letters, all of which were passed to the Institute.
Responses to the article pointed to the need to simplify Russian spelling due to the use of Russian as the language of international communication in the Soviet Union and an increased study of Russian in the Eastern Bloc as well as in the West. That instruction for non-native speakers of Russian was one of the central concerns of further reform is indicated in the resistance to Efimov's proposal to drop the terminal "?" (soft sign) from feminine nouns, as it helps learners identify gender category. Additionally, Efimov claimed that a disproportionate amount of primary school class time was devoted to orthography, rather than phonetics and morphology. Efimov asserted that the existing orthography was essentially unchanged since Grot's codification, and that only by bringing orthography closer to phonetic realization, and eliminating exceptions and variants, could appropriate attention be paid to stylistics and the "development of speech culture". The state's focus on proper instruction in Russian, as the national language of ethnic Russians, as the state language, and as the language of international communication continues to the present day.
[...] the Russian spelling reforms of 1917-1918 were based on proposals drawn up by an imperial commission thirteen years earlier, slightly watered down. However, because they were implemented at time of great social upheaval, these reforms divided Russian literati into two camps. Adherence to the old orthography became a mark of adherence to pre-revolutionary values, and some émigré presses continued to employ the pre-Soviet conventions until the 1970s.