Purpose of parts` headings in Psalter of tsar Ioann Groznyj

For studying of Russian book culture Psalter is of great importance. The parchment Psalter written at the end of the XIV century, belonging at XVI century to Tsar Ioann Groznyj, is an outstanding example of old Russian literatire (Russian State Library, collection № 304, № 7, last third of the XIV century). Titles of parts in Psalter of Tsar Ioann Groznyj are multifunctional. First of all, they accentuate the beginning of the text. This headings are situated just in the beginning of the book, in foreword, above kathisms and psalms, above tropars and prayers, in «Bible songs». Therefore they are very important for analysis of book's content and textual criticism. Headings of psalms carry out informational and hermeneutic function, headings of prayers also didactic function, determining the rules of reading. Beauty and originality of graphic design demonstrate also the aesthetic function of headings.