Support for standard numbering schemes

The current bookmap prototype includes support for an ISBN number. I wonder whether this should be extended to support other common numbering schemes such as

* Digital Object Identifiers (www.doi.org)
* ISSN (www.issn.org)
* Persistent URLs (http://purl.oclc.org/)

The inclusion of elements for <edition> and <volume> seem appropriate for serial publication which would carry an ISSN number.

Many publications would use one or more of these standards for example ISSN and DOI are commonly used together.

In most instances these standards would also be appropriate to be defined in the ditamap rather than just in bookmap. For example, an ISBN number can be used for a CDRom publication that is intended for output in human readable form, or whose content is comparable to that available in printed form.

Regards

Mark Poston
Mekon Limited
www.mekon.com
Tel: +44 (0)20 8722 8461
Skype: mark_mekon.com