There’s been a discussion of the (Mexican) Spanish term fojas utiles. Two points came up here: firstly, these may be ‘sheets with valid text’ – at least, the other sheets are either blank or crossed out (inutilizadas). Short lines may be used to fill up a ‘blank’ page so nothing can be entered there. I thought this was interesting because I can remember some German birth certificates contain a line with the words ‘eine Zeile’ (a line), which I suppose is the same thing. I’ve never found a source for information on the procedure for documents. I doubt there is one online – this kind of thing would be in materials for court office staff and that kind of thing.

The second question relates to the term sheets – would not pages be better? A sheet (the term was new to me) means a leaf of paper with a front (recto) and a back (verso). Actually, I know the term folio rather than sheet for this. One always wonders whether to use it when the German reference to a big register says Blatt.

OED:

folio: 1. A leaf of paper, parchment, etc. (either loose as one of a series, or in a bound volume) which is numbered only on the front. … recto/verson
2. In Bookkeeping, The two opposite pages of a ledger or other account-book in which these are used concurrently …

One commenter said that in archival speak, the term is leaf, which can have a front and back. Although people do talk about the fronts and backs of pages, this isn’t correct.

The Chicago Manual of Style (14th ed., 1.1), for the USA:

The trimmed sheets of paper that make up a book are often referred to as leaves. A page is one side of a leaf. The front of the leaf, the side that lies to the right in an open book, is called the recto page (or simply recot). The back of the leaf, the side that lies to the left when the leaf is turned, is called the verso. Rectos are odd-numbered pages; versos are even-numbered.

New Hart’s Rules, for the UK, confirms this use of leaf, recto and verso, and also introduces the term spread or opening.

But when it comes to folio, things get more confusing. Folio can mean a page number, which is not relevant here. Or it can mean a sheet of a typescript, which should be printed on one side of the paper only.

My conclusion is that the correct term for Blatt is leaf, but the terms sheet and folio are more generally used. Page is not correct.

All clear as mud.