OpenURL

OpenURL is a NISO standard syntax for transporting information (metadata and identifiers) about one or multiple referents within URLs. OpenURL provides a syntax for encoding metadata (but not a source of it), restricted to the world of URLs (unlike the DOI system’s wider application). This interface can be used to tie together otherwise disparate services such as centralized resolution systems and local knowledge of available referents. The logically centralized resolution service maintained by the content producers for DOI names has no way to resolve a DOI name to a locally held copy of the identified entity. So the synergy between the DOI system and OpenURL is clear: OpenURL needs a source of identifiers and authoritative metadata; the DOI system provides a single point in the network for the creation and subsequent redirection of OpenURLs, which is more manageable than asking every content provider to enable this facility. Solving the appropriate copy problem is a significant accomplishment in and of itself, but there are many opportunities for productive collaboration beyond that. An OpenURL consists of a base URL followed by a query for one or more objects. So: sends an OpenURL compliant request to a receiving service provided by getlocal at the location specified with a query with the parameter author and the value Shelley. What is not seen in the syntax is that the service will also receive any information about the user that may be sent along by default with the request as part of any authentication that has taken place between the users client and the server. The local service can then decide, based on the metadata sent and what the server knows of the user’s credentials, how to respond to the request. DOI names can be used within the OpenURL syntax to query local services about availability of referents at a local level, e.g. the following could be used to see if a local copy of a referent were available: The local service could have a list of DOI names that it has a local service for and offer that alongside the global information services obtained by resolving the DOI name through the Global Handle Registry. OpenURL also allows more complex constructs that those illustrated above. The comparison of OpenURL enabled systems with the DOI system is straightforward: the DOI system is a global system; all information about a referent is the same in the global system wherever the DOI name is resolved from; the data that is associated with a DOI name can be modified, and extended, and is not locked into embedded implementations. Even if an OpenURL carried all data that could be obtained from a DOI name at a particular point in time, it would be static when used as a pointer in a document. Thus the DOI system provides an authoritative centralized resolution system with careful control of the results of the resolution process. Additionally this identifier can be resolved to multiple pieces of information, including pointers to well-structured metadata. The OpenURL Framework was developed and approved as NISO standard ANSI/NISO Z39.88 The OpenURL Framework for Context-Sensitive Services . Additional information and KEV Implementation Guidelines are available from NISO . 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. 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. 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 Referen