Despite its long association with the monastery of Sant'Eutizio (in the Vallecastoriana region of Umbria, near present-day Preci, Italy), paleographic evidence suggests that C.5 was originally produced in Rome. The script, a carolina romana of the later eleventh century, and the notation, "transistional" type often called "italo-beneventaine," both suggest that the manuscript originated in Rome; indeed, script and notation are quite similar to those of the Old Roman Antiphoner (Città del Vaticano (Roma), Biblioteca Apostolica Vaticana, Archivio San Pietro B.79). The manuscript appears to have been used by the nuns at San Sisto Vecchio until they came under the care of the Dominican Order in 1219. It seems then to have been sent to the monastery of Sant'Eutizio di Norcia, where numerous additions and corrections were made. Analysis of these indicates that C.5 was revised to conform to liturgical practice of Rome, Biblioteca vallicelliana C.13, a notated breviary containing the Winter Temporale and Sanctorale according to the use of Sant'Eutizio. A catalogue of the first 150 folios of C.5 (accompanied by a catalogue of the entire contents of C.13) appears in the dissertation of Jacob Carl Ledwon. The manuscript contains a large number of chants that are not to be found in Hesbert's >Corpus Antiphonalium Officii: these include verses and prosulae for CAO responsories, as well as entire Offices not present in CAO. Verses or prosulae associated with CAO responsories but not actually included in that resource have been assigned CAO numbers corresponding to those of their parent chants; the numbers for all other chants not found in CAO are prefixed by "rva". Differentiae are numbered arbitrarily.
- Huglo, Michel. Les tonaires: Inventaire, analyse, comparison. Paris: Heugel et Cie, 1971. (See p. 201.)
- Ledwon, Jacob Carl. "The Winter Office of Sant'Eutizio di Norcia: A Study of the Contents and Construction of Biblioteca Vallicelliana Manuscripts C 13 and C 5." Ph. D. diss., State University of New York at Buffalo, 1986. (See especially pp. 68-95.)