Background
The OpenURL Framework is a syntax for transporting metadata and/or identifiers about an object, using an established set of parameter names, to enable context-sensitive linking for the development of user-specific services. It has been developed and approved as NISO standard ANS/NISO Z39.88 The OpenURL Framework for Context-Sensitive Services. Additional information and KEV Implementation Guidelines are available from NISO Committee AX.
The OpenURL Framework includes DOI names as one of its registered Namespaces and DOI names are widely used in OpenURL implementations. This documentation references only part of the OpenURL Framework Registry. More references to OpenURL and the DOI® System proxy server will be found in the documentation on Parameter Passing.
The DOI® System Proxy Server and OpenURL
In the OpenURL Format, descriptions of referenced resources, and descriptions of the associated resources that explain the context of the resource, are contained in ContextObjects that are transported using the HTTP protocol. ContextObjects use a Key/Encoded-Value format to create a string of ampersand-delimited pairs. The values must be URL-encoded.
Of the five ContextObject Entities, one of them, the Referent, is required. Within the scholarly information community, the Referent will likely be a journal or journal article, a conference proceeding, or a book. The Identifier for the Referent is its DOI name.
The DOI System proxy server is a web server that understands the Handle System® protocol. It is not an OpenURL Resolver per se, and does not provide services to an end-user that pertain to the Referent within the ContextObject of the OpenURL. When it receives an OpenURL, it finds the DOI name in the string, resolves it, and re-directs the end-user's browser to that URL, ignoring all other ContextObject Entities.
The default syntax for a DOI name resolution request to the proxy server is:
http://dx.doi.org/10.1000/demo_DOI_name
The same DOI name resolution request using OpenURL would be:
http://dx.doi.org/openurl?url_ver=Z39.88-2004&rft_id=info:doi/10.1000/demo_DOI_name
The OpenURL Format standard approved by the NISO voting members includes significant changes made between Versions 0.1 and 1.0. Relevant to DOI names, in OpenURL Format Version 1.0, 'rft_id' replaced 'id' which was used in Version 0.1.
There were also changes to Namespaces. All Namespaces now follow URI schemes, and the 'uri:' prefix was dropped. ORI Namespaces are now 'info:'.
Also note that the initial implementation of OpenURL in the DOI System proxy server using the 'rft_id=doi:10.1000/demo_DOI_name' syntax will continue to be supported.
