Q. When citing the recto and verso side of a folio page, I was curious as to which abbreviation was correct: fol. 1r–v, or fols. 1r–v. I had presumed it was the former because one folio has a recto and verso side, but I found a lot of precedent for the plural in publications from the University of Chicago Press and other reputable academic presses (including Cambridge and Oxford). Is one of these options preferred, or are both correct? Thanks for your help with this.
A. The word folio in the context of book pages refers to the leaf of paper, including both sides, so you’re right that “fol. 1r–v” would make sense. But folio can also mean “page,” so “fols. 1r–v” could also make sense. If we had to side with one, however, it would be the singular. The plural would then be reserved for multiple leaves:
fol. 1r (the recto of folio 1, or one page)
fol. 1r–v (the recto and verso of folio 1, or two pages)
fols. 1r–2v (the recto and verso sides of folios 1 and 2, or four pages)
For an example of this usage, see the annotations for this ninth-century parchment manuscript at the Bodleian Library. And though you’ve found examples out there that depart from this usage, a Google search comparing “fol. 1r–v” with “fols. 1r–v” (and the like, with 2r–v, 3r–v, etc.) suggests that the singular is significantly more common.