Comparative studies of medieval Church Slavonic Gospel manuscripts – whether broad-scale taxonomies of textual traditions, identifications of manuscript families, or analysis of features of a single manuscript – require a large corpus of manuscripts from which a subset can be selected for comparison. This paper proposes some desiderata for an electronic collation of medieval Slavic manuscripts and discusses some anticipated philological and methodological issues that would need to be resolved during the development of the collation with computer tools. The project is base on the material from medieval menologies or calendars of saints in the Slavic Gospels.