This article is dedicated to the "Primer" of Karion Istomin. It focuses on a particular copy created by the Moscow scribe and "children's teacher" Diomid Serkov with handwritten additional material from the "School Decorum" ["Shkol'noye blagochinie"]. This primer is an example of a special book type that arose in Russia during the second half of XVII century. [This article was translated by Kenneth Cargill.]