externalDocumentDefRef 

A name, URN or other reference that cites an external specification or reference that defines the document. This attribute was added during v2.0.1 Public Review and included in v2.0.2.

Attribute Information

Used By

Element Specification

Source 

<xsd:attribute name="externalDocumentDefRef" type="xsd:normalizedString" use="optional">
  <xsd:annotation>
    <xsd:documentation>A name, URN or other reference that cites an external specification or reference that defines the document. This attribute was added during v2.0.1 Public Review and included in v2.0.2.</xsd:documentation>
  </xsd:annotation>
</xsd:attribute>

Sample