The thesis analyzes the non-standard vowel length and shortness in the complete hymn book of Valentin Šubar, as it is presented in the edition published by the Utraquist Jiří Hanuš of Kronenfeld in 1612 (Knihopis K16012). Based on selected transliterated segments, the level of consistency in the marking of vowel quantity is identified, and the outcome is subsequently taken into account when interpreting individual non-standard forms. Consequently, the results of previous research on vowel length marking in the 17th century Czech prints are slightly modified and the incorrect datation of surviving exemplars of the hymn book is corrected.