The name of the scheme according to which the metadata record identifier is assigned by the authority that issues it (e.g., DOI, URL, etc.)
Source
<xs:element name="MetadataRecordIdentifier" type="ms:MetadataRecordIdentifier"><xs:annotation><xs:documentation xml:lang="en">A string (e.g., PID, DOI, internal to an organization , etc.) used to uniquely identify a metadata record</xs:documentation><xs:appinfo><identifier>http://w3id.org/meta-share/meta-share/MetadataRecordIdentifier</identifier><label xml:lang="en">Metadata record identifier</label><subclassOf>http://purl.org/spar/datacite/ResourceIdentifier</subclassOf></xs:appinfo></xs:annotation></xs:element>