What is the best way to preserve page numbers from InDesign to EPUB?

Question

I have a project where the source files are InDesign based - the final step before the product goes to print.  We want to bring this content to reflowable EPUB format, but we need to keep the print page numbers in order to support citations.
Has anyone faced this type of challenge previously, and what was the approach pursued?  While an InDesign 2014 export to EPUB Fixed will preserve the page numbers, there will be a lot of cleanup required to make these files reflowable again.
Andre

Answer 1

Hi Douglas,
I agree that the common practice of removing the page numbers works with regards to trade content (fiction, non-fiction, magazines, etc) where pages generally are to communicate how far you have 'travelled' in a particular title.  With reference works, however, this particular type of metadata can have a greater meaning - communicating to other individuals the location of a reference in order to allow them to see the reference in its original context.  It becomes a way of locating relatively precise locations within a work that is being referenced.
Currently, and we can expect for some time, the original print content will be the authoritative version that is referred to, or cited, as a means of communicating the exact location of a specific reference to another individual.  Although evident in many industries, perhaps this arises most commonly in legal texts, where a lawyer as part of an argument or a judge in writing a decision will cite a text reference by title, volume, possibly edition, date/year, etc. and, ultimately, the page number - which in the end is just another piece of metadata relative to the text that appears on that particular page.  In order to create digital copies of these types of texts that can still function relative to the print authority, an accurate page number that corresponds to the print needs to be available somewhere in the texts.  (This is true both ways, by the way - both in terms of following a cite to a specific location within the content; and citing a specific location within the content).
For many publishers, InDesign will be the final, what I would call 'exportable' format that can maintain a certain degree of information about the context of the source content and will have page numbers represented that precisely reflect what will be found in the final print version.
I have some ideas on how I would like to present this in a reflowable digital version (and reflowable text for this type of content is desirable for all the reasons it would be elsewhere - adaptability to screen size, ability to resize/change fonts for different reader experience, etc). And the new EPUB fixed export function will allow me to preserve the page numbers and through some programming I can get to a point where I can isolate the text that corresponds to a specific page number from the InDesign exporta manual solution would not be an improvement), but with a somewhat 'cleaner' export of the text of the content, where the precise fixed formatting is not so important.
The perfect solution would be to allow page numbers to be preserved within a 'hidden' tag in the EPUB reflowable export - so that the content of each page would be preceeded by an <a id="Page_75" /> tag, with words that are hyphenated belonging to the page on which they started.  Note that the use of such a tag would also go a long way towards supporting the call for a "page-list" and hyperlinks as you've described them above.  If the publisher wanted to make use of such a tag, it would be available to them - otherwise the tag would be ignored by publisher and eReader software alike.
Andre