The database contains data on the contents of the parochial book collections in King Stanisław August's times in four Roman Catholic Dioceses: Płock, Vilnius, Kraków and Chełm and the Greek Catholic Diocese of Chełm. In the database, I present the administrative division of 1772 in order to avoid the chaos resulting from subsequent organisational1 changes.

This website is not a source edition but a study. I do not present the source wording of book names but identified titles or only authors depending on the details of the information contained in the inventory. I decided not to edit the source due to the nature of the research. The method of describing books was highly diverse and therefore the correct edition would be very time-consuming, while in some archives and libraries it is impossible to perform digital reproductions.

In traditional appendices included in studies on parochial book collections, data is presented in one way only. The list of authors is provided and the parishes in which a given book has appeared are assigned to them or the contents of the book collections in individual parishes is presented. The present database combines both ways and enables data browsing using a geographical and bibliographic query. In a similar way, the data was presented by dr Joanna Szady (PhD) in the online journal Atlas Fontium, in which information was additionally presented on a map.