There is no such thing as rft.identifier. There is an rft_id -- it's with the underscore, not a period, because it's not a data element in a _particular_ OpenURL format, rather it applies to any OpenURL format. rft_id can be set to any URI (although that URI does need to be itself URI-encoded, confusingly). Typical uses are for an OCLC number or an LCCN. I use rft_id to represent my own local accession numbers. First I represent them as a URI: http://catalog.library.jhu.edu/10001. Then you need to URI-encode that to put it in the KEV OpenURL such as is the basis of COinS: rft_id=http%3A%2F%2Fcatalog.library.jhu.edu%2F10001 That's probably the best solution you are going to get out of OpenURL/COinS. Yes, it is annoying in a few different ways. Jonathan Chris Catalfo wrote: > Hi all, > > I am trying to find the best way to include an item's accession number (i.e. > ILS system id) in a COiNS span. This is in the context of library catalog > pages where I'd like to be able to retrieve the ILS accession number to > return to LibraryThing for Libraries. > > I see no mention of an rft.identifier key/value pair on the COiNS site's > brief guide to books [1]. It does, however, appear as an element in the > COiNS online generator for generic items [2]. > > Googling returned a couple of results using rft.identifier to hold urls. > > Can anyone enlighten me as to whether using rft.identifier to hold the ILS > accession number is valid? Or suggest a more suitable key/value pair? > > Thanks for any help you can provide. > > Chris Catalfo > Programmer, LibraryThing > > [1] http://ocoins.info/cobgbook.html > [2] http://generator.ocoins.info/?sitePage=info/dc.html& >