Differentiae are written in-line, at the end of each antiphon. In the original index, they were identified using a two-digit system: an upper-case letter indicating the last pitch of the differentia and a number to distinguish between differentiae in the same mode with the same last pitch.
Sandler, Elizabeth. Inventory of Wien, Österreichische Nationalbibliothek - Handschriftensammlung, 1799**. Edited by Andrew Mitchell. In: Cantus: A Database for Latin Ecclesiastical Chant: Inventories of Chant Sources. Directed by Debra Lacoste (2011-), Terence Bailey (1997-2010), and Ruth Steiner (1987-1996). Web developer, Jan Kolácek (2011-).
Images: Antiphonar, Cod. 1799**, Sammlung von Handschriften und alten Drucken, Österreichische Nationalbibliothek
Standardized manuscript tonary completed by Rebecca Shaw (Dalhousie University) on March 11, 2018. Edited by Jennifer Bain, Sister Ilaria Culshaw, Andrea Klassen, and Brayden Olson and (Dalhousie University) on August 8, 2019 and Rebecca Shaw on August 11, 2019.