Any DOI name which is intended for interoperability — that is, which has the possibility of use in services outside of the direct control of the issuing RA — is subject to DOI metadata policy:
•The DOI Kernel Metadata ensures that the minimum set of metadata held by different RAs is consistent.
•The interchange provisions of the additional metadata exchange schemas and of the data dictionary ensure that an efficient and extensible means of interchange exists for transporting metadata between RAs (and in future other service providers).
The figure below shows how interoperability is achieved when the content rendering service of an RA (RA1) processes DOI names managed by another RA (RA2). In this example, the content rendering service of RA1 receives metadata about a DOI name managed by RA2. To be able to process this metadata, RA1's service uses, in addition to the DOI Kernel Schema, the metadata exchange schema agreed between RA1 and RA2.
