Hyperref and repeated page numbers

The book class (and its friends and relations) automatically changes the display of page numbers in the frontmatter of the document to lower-case roman. This is fine for human readers, but if hyperref has been misconfigured, the existence of pages have the same page number can cause problems. Fortunately, the configuration options to make hyperref “do the right thing” are (by default) set up to avoid problems.

The two options in question are:

• plainpages=false Make page anchors using the formatted form of the page number. With this option, hyperref writes different anchors for pages “ii” and “2”. (This is the default value for the option, which is a good thing…) If the option is set true hyperref writes page anchors as the arabic form of the page number, rather than the formatted form that gets printed; this is not usually appropriate.
• pdfpagelabels Set PDF page labels; i.e., write the value of \thepage to the PDF file so that Acrobat Reader can display the page number as (say) “ii (4 of 40)” rather than simply “4 of 40”.

The two should be used whenever page numbering is not just “1…n”; they may be used independently, but usually are not.

The recipe isn't perfect: it relies on \thepage being different for every page in the document. A common problem arises when there is an unnumbered title page, after which page numbers are reset: the pdfTeX warning of “duplicate destinations” will happen in this case, regardless of the options.