Now, I heard of footnotes per page, section, chapter, part or document, used all of them, but recently I got a (strange?) request to have footnote counter reset per page spread, i.e., after every odd page.
The point thrown at me is the following: in a book, there should never ever be the same footnote number present on both even and odd page in a page spread (as happens regularly when "perpage" footnote method is used), because the page spread should be observed as a whole, not the page alone. According to this, numbering the first footnote on both even and odd page with number 1 is unacceptable.
So, my question is: what is the easiest and/or safest way to have footnote counter reset after every odd page, so that footnote numbering starts anew on every even page? In the example code below, footnote numbers should start anew on pages 2 and 4.
Also, I'll appreciate any thought, theoretical explanation or reference which approves or disapproves this kind of footnote numbering.
\documentclass{book}
\begin{document}
First\footnote{A footnote}\par
First\footnote{A footnote}\par
First\footnote{A footnote}\par
\clearpage
Second\footnote{A footnote}\par
Second\footnote{A footnote}\par
Second\footnote{A footnote}\par
\clearpage
Third\footnote{A footnote}\par
Third\footnote{A footnote}\par
Third\footnote{A footnote}\par
\clearpage
Fourth\footnote{A footnote}\par
Fourth\footnote{A footnote}\par
Fourth\footnote{A footnote}\par
\clearpage
Fifth\footnote{A footnote}\par
Fifth\footnote{A footnote}\par
Fifth\footnote{A footnote}\par
\end{document}