Old Novgorod dialect (; also translated as Old Novgorodian or Ancient Novgorod dialect) is a term introduced by Andrey Zaliznyak to describe the dialect found in the Old East Slavic birch bark writings ("berestyanaya gramota"). Dating from the 11th to 15th centuries, the letters were excavated in Novgorod and its surroundings. For linguists, Old Novgorodian is particularly of interest in that it has retained some archaic features which were lost in other Slavic dialects, such as the absence of second palatalization. Furthermore, letters provide unique evidence of the Slavic vernacular, as opposed to the Church Slavonic which dominated the written literature of the period. Most of the letters feature informal writing such as personal correspondence, instructions, complaints, news, and reminders. Such widespread usage indicates a high level of literacy, even among women and children. The preserved notes display the original spelling of the time; unlike some texts, they were not copied, rewritten or edited by later scribes. Today, the study of Novgorodian birch bark letters is an established scholarly field in Russian historical linguistics, with far-ranging historical and archaeological implications for the study of the Russian Middle Ages. History The first birch bark letter was found on July 26, 1951, by Nina Fedorovna Akulova. At least 1025 have been unearthed since, 923 in Novgorod alone. Almost all of them were written with styluses of bronze and iron, and never ink. The letters were preserved due to the swampy soil which isolated them from oxygen. Many letters are found buried amidst the layers under streets which were previously paved with logs. Linguistic features The short birch-bark texts are written in a peculiar Slavic vernacular, reflecting living speech, and almost entirely free of the heavy Church Slavonic influence seen in the literary language of the period. Some of the observed linguistic features are not found in any other Slavic dialect, representing important Proto-Slavic archaisms. Zaliznyak differentiates the Old Novgorod features that were already known before the discovery of the birch bark letters and those that have been ascertained after their study during the last few decades such as the following: tsokanye secondary pleophony, e.g. мълъвити as opposed to мълвити retention of stem-final *x in Proto-Slavic *vьx- "all" (spelled вехь) whereas other Slavic languages have undergone the third progressive palatalization, e.g. вьхо () lack of the Slavic second palatalization in root-final position, e.g. рукѣ, моги the change vl’ > l’, e.g. Яколь, Яковлев