Recommended
identifier or multilingual free text
ms:resourceIdentifierSchemeName or ms:schemeURI (for identifiers) and xs:lang (for names)
A name or an identifier (e.g. url reference) to the component used for the annotation of the resource
The recommended way for referring to a resource is by giving its name and its identifier; if you provide the identifier, please select also the relevant value from the list of values in the attribute "resourceIdentifierSchemeName"; if none is appropriate, please select "other" and use the "schemeURI" attribute to provide a link to a URL with more information about the identifier scheme.