CrossRef's MR service provides an interim page solution which presents a list of link choices to the end user. Each choice represents a location at which the item may be obtained and are commonly services that are co-hosting the content under agreement with the content's Copyright holder.
MR operates by changing the DOI's URL to point to a service hosted at CrossRef which uses a HTML template to present a branded page to the end user. Templates may be assigned on a title or prefix basis (e.g. unique template per publication title or one template for all titles associated with a given prefix).
Key to the new MR service is the enforcement of roles and permissions. Based on prefix, user accounts will be permitted to deposit primary or secondary metadata for any DOI owned by that prefix. Primary deposits include registration of the DOI itself and metadata includes all bibliographic data and the URL for the primary site at which the content is hosted. Primary deposits are essentially the 'traditional' form of deposit. Secondary deposits consist only of additional URLs to be attached to the DOI (secondary depositors can not create DOIs). Users making primary deposits need not be involved in the activity performed by a secondary user but the primary content owner must enable each DOI that may receive additional URLs. Secondary depositors are responsible for knowing the DOI to which they are going to attach a URL, they can determine this by reviewing the metadata of the primary depositor.
The steps involved in executing MR are as follows:
A CrossRef administrator must enable the secondary depositor's account to make MR deposits
Definitions
Content owner: The organization that holds copyright for the content or is known as the publisher
Secondary depositor: A co-host for content who has been authorized by the content owner to serve the content on-line
Prime URL: The URL of the content located on the content owner's site. This may be a site maintained directly by the content owner or it may be a service provider acting on behalf of the content owner
Default URL: The DOI resolver (aka proxy) primarily operates by selecting a single URL for a DOI when servicing a resolution request and redirects users to that URL, known as the default URL. When no MR activity is occurring the default URL is the same as the prime URL.
Interim page: Due to the need to maintain compatibility with simple HTML constructs (e.g. the href in an anchor tag) an interim page is used to present end users with choices. In this model a DOI's default URL is set to that of an interim page service and its prime URL is then offered as one of multiple choices to the end user.