This article records tradition as it has been passed down and reported. Its sources are not yet part of the atlas's verified catalogue.
Cyrillic Letters gathers the forty three signs of the alphabet made for Slavonic worship, showing how a script built mostly from Greek letterforms carries a numbering system, a set of native additions, and a small tail of signs kept only for spelling Greek words.
The first ten letters recite as a sentence, azu buky vedi glagol dobro jest, I know letters, speaking is a good thing, and the pattern continues through kako lyudiye myslete, how people think, before the names run out of sense at tverdo. Cyrillic takes its numerals from Greek letter for letter, so vedi carries the two that Greek beta holds once its sound had shifted to v, leaving buky, the letter it actually replaced, with no numeral at all; that borrowing is why the Cyrillic count and the Glagolitic count of the same letters disagree at almost every point.
Where Slavonic had a sound Greek lacked, the alphabet borrowed a shape from Glagolitic instead, zhivete, tsy, cherv, sha and shta among them, and none of those five carries a Greek numeral. The two jers, yer and yeri, wrote reduced vowels that later Slavic either lost or turned into the modern hard and soft signs, and the yus letters recorded nasal vowels that survived in Bulgarian orthography into the twentieth century. Ksi, psi, fita and izhitsa exist only to spell Greek names and were dropped from Russian civil printing under Peter the Great, though they remained in church books.