In the original Cantus index, differentiae were assigned two-digit codes, where the first letter indicated the last pitch of the differentia and the number distinguished between differentiae of the same mode had the same last pitch. The same codes were used for the indices of B-TO olv 63, B-TO olv 64, and NL-DHk 70 E 4.
de Loos, Ike. Inventory of Tongeren, Onze-Lieve-Vrouw-Kerk (Our Lady's Church), 63 (olim V). 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-).
Standardized manuscript tonary completed by Rebecca Shaw (Dalhousie University) on March 19, 2019. 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.