With the multiple DOI resolution, multiple resources in potentially any format can be managed in the DOI record. The multiple resolution is typically used to manage several URLs of the same referent (see Management of a Referent with Several Instances ) or to select a different URL according to various criteria.
To manage multiple resources in the DOI record, an element of the predefined type 10320/LOC is used. This element allows specifying complex rules formatted in RDF/XML which can be interpreted by the DOI resolver to retrieve the resources to be returned to the resolution requester. For example, a resource may be selected according to the context of the request (in particular, to the country of the requester). For more information, see 10320/LOC Element.
The following figure shows a DOI record containing a 10320/LOC element used to retrieve URL(s). The 10320/LOC element could also be stored at prefix level, thus applying to all DOI names under that prefix.
The multiple DOI resolution process is as follows:
1.A requester (user or application process) sends an HTTP request to the DOI resolver.
2.The DOI resolver sends a resolution request of the DOI name to the GHR. The GHR redirects the resolver to the responsible DOI LHS which returns the DOI record to the resolver.
3.The DOI resolver recognizes the 10320/LOC element. Depending on the HTTP request features, the DOI resolver may interpret the code it contains and return the interpretation result (for example, an URL) to the requester; or it may return the raw XML code, or a list of possible resources (for example, a list of URLs).
If there are DOI resolvers (other than the DOI Proxy) that do not understand the 10320/LOC type, these resolvers would ignore it and simply apply a single DOI resolution request.