OpenURL
metadata, identifier or locator forms a ‘citation’ for the resource
OpenURL - way to encode citation for a resource
OpenURL = BaseURL + Description
BaseURL provides location of a ‘resolver’
Description is either a global identifier (e.g. a DOI or ISBN) or a description (a citation) or mixture
http://sfx.bath.ac.uk/sfxmenu?genre=book&isbn=1234-5678