att.canonical provides attributes that can be used to associate a representation such as a name or title with canonical information about the object being named or referenced. [13.1.1. Linking Names and Their Referents]
Membersatt.naming [att.personal [addName forename genName name objectName orgName persName placeName roleName surname] author birth bloc collection country death district editor event geogFeat geogName institution offset origPlace pubPlace region repository rs settlement state] authority catDesc correspDesc date distributor docAuthor docTitle funder material meeting object objectType principal publisher relation resp respStmt sponsor term time title unitDecl unitDef
keyprovides an externally-defined means of identifying the entity (or entities) being named, using a coded value of some kind.
Status Optional
Datatype teidata.text
 <name key="name 427308"
[New Zealand Parliament, Legislative Council]</name>
 <name key="Hugo, Victor (1802-1885)"
Victor Hugo</name>

The value may be a unique identifier from a database, or any other externally-defined string identifying the referent.

No particular syntax is proposed for the values of the key attribute, since its form will depend entirely on practice within a given project. For the same reason, this attribute is not recommended in data interchange, since there is no way of ensuring that the values used by one project are distinct from those used by another. In such a situation, a preferable approach for magic tokens which follows standard practice on the Web is to use a ref attribute whose value is a tag URI as defined in RFC 4151.

ref(reference) provides an explicit means of locating a full definition or identity for the entity being named by means of one or more URIs.
Status Optional
Datatype 1–∞ occurrences of teidata.pointer separated by whitespace
<name ref=""
Seamus Heaney</name>

The value must point directly to one or more XML elements or other resources by means of one or more URIs, separated by whitespace. If more than one is supplied the implication is that the name identifies several distinct entities.