What bookdealers really mean. A dictionary by Tom Congalton and Dan Gregory (Between the Covers), with additions from other sources
The "back" side of a page in a book, that is the page that is on the left-hand side of a book when it is opened. Many people get the terms recto and verso confused, but our favorite was when we read an essay on book collecting by a bookseller that referred to the "reverso" of a page, which we felt had a certain zen-like quality to it as a descriptive term (unless he was referring to the superhero book collector able to return prices to what they were in his youth).
l'envers d'un feuillet
Die Rückseite eines Blatts. Das Gegenteil von recto.