Although this manuscript is part of a collection of medieval music manuscripts held at the male Augustinian monastery of St. Florian, due to the inclusion of chants for Wolfgangus, Bishop of Regensburg, and similarities in its liturgical order with sources from the Diocese of Regensburg (e.g. London, British Library, printed book IB. 6753), Dobszay and Klugseder both suggest that the manuscript is from Regensburg. There is also some discrepancy over the date of the manuscript; the library catalogue for St. Florian places the manuscript in the fourteenth century, but Dobszay suggests that it is more likely from the thirteenth century.
Throughout this manuscript, differentiae for antiphons are given in the margins, apparently in the original hands. These are often accompanied by modal designations in lower-case Roman numerals, also in the original hands.
When the mode is not indicated, it can be determined if the exact neume forms of the differentia are given an explicit modal designation elsewhere in the manuscript. In such cases and others in which the mode is evident, but not given explicitly for the particular chant, the mode number is entered into the mode field, but followed by a question mark. If there is any ambiguity, a mode has not been assigned. Differentiae are numbered for each mode in no particular order. There is a series of differentiae for antiphons whose modes cannot be determined. These are characterized by having only a question mark in the mode column. Modes for responsories are provisional; they are based on the neume forms of the eight verse tones and comparison with the other sources in the database. Because of their provisional nature, all mode numbers for responsories are followed by a question mark. Again, if there is any ambiguity (such as in cases where a non-standard tone is given for a verse), a mode has not been assigned.
- Dobszay, László. "The Secular Liturgical use of Regensburg: Two New Sources." In Ars musica – musica sacra, 69–98. Ed. David Hiley. Tutzing: Hans Schneider, 2007.
- Jahn, Michael, and Andreas Lindner. Die geistlichen Werke. Vol. 2 of Die Musikhandschriften des Augustiner-Chorherrensiftes St. Florian. Vienna: Veröffentlichungen des RISM-Österreich, 2007.
- Klugseder, Robert. "Mittelalterliche music-liturgische Quellen aus dem Augustinerchorherrenkloster St. Florian." Musicologica Austriaca 31 (2012): 13–82.
- Digital images are available through the site "Musikalische Quellen des Mittelalters in der Oesterreichischen Nationalbibliothek," (available from http://www.cantusplanus.at/en-uk/cantus/index.htm). Click and scroll to find: "Antiphonar für den Gebrauch in der Diözese Regensburg - A-SF XI 480."