Mall:Citation Style documentation/volume

• volume: For one publication published in several volumes. Displays after the title and series fields; volume numbers should be entered just as a numeral (e.g. 37); volume values that are wholly digits, wholly uppercase Roman numerals, or less than five characters will appear in bold. Any non-numeric value of five or more characters will be presumed to follow some other convention and will not appear in bold. In rare cases publications carry both, an ongoing volume and a year-related value), if so, provide them both, for example |volume=IV / #10.