<xs:element maxOccurs="unbounded" name="ThesaurusConcept" type="ThesaurusConceptCoreStructure"> <xs:unique name="TermIdentifier"> <xs:selector xpath="bs8723:ThesaurusConcept/bs8723:PreferredTerm|bs8723:ThesaurusConcept/bs8723:NonPreferredTerm"/>
<xs:field xpath="@dc:identifier"/>
</xs:unique> <xs:unique name="PreferredTermIdentifier"> <xs:selector xpath="bs8723:ThesaurusConcept/bs8723:PreferredTerm"/>
<xs:field xpath="@dc:identifier"/>
</xs:unique> <xs:unique name="NonPreferredTermIdentifier"> <xs:selector xpath="bs8723:ThesaurusConcept/bs8723:NonPreferredTerm"/>
<xs:field xpath="@dc:identifier"/>
</xs:unique> <xs:keyref name="UF" refer="NonPreferredTermIdentifier"> <xs:selector xpath="bs8723:ThesaurusConcept/bs8723:PreferredTerm"/>
<xs:field xpath="bs8723:UF"/>
</xs:keyref> <xs:keyref name="USE" refer="PreferredTermIdentifier"> <xs:selector xpath="bs8723:ThesaurusConcept/bs8723:NonPreferredTerm"/>
<xs:field xpath="bs8723:USE"/>
</xs:keyref> </xs:element>