2.2.2 Arabic Numbers

Use arabic numerals rather than roman numerals in most contexts: 1, 10, 25, not I, X, XXV. This applies especially to bibliographic information, including volume numbers, edition numbers, and most numbered references.

This also applies to ordinary citations of primary sources: AL 3:12, not AL III:12.

Roman numerals may be retained where they are part of an established title (e.g., Liber LXI vel Causæ), a formal numbering system, or the source’s own citation convention. Common exceptions include front-matter page numbers, manuscript or catalog numbers that traditionally use roman numerals, tarot when cited by traditional number and title (e.g., Atu XIV: Art), and works whose titles include roman numerals. Other exceptions should be identified by the editor and recorded in the project style sheet.