<xsd:annotation>
<xsd:documentation> Identifies a similarity relationship between this design and a principal design or to indicate that this design is the main
design to which other designs relate to. "This design" refers to the parent dgn:HagueDesign context. In the context of the
Hague system when the PrincipalDesignCategorydgn:PrincipalDesignCategory is set to "Current application" or "Main design" in a dgn:HagueApplication, the value of com:OfficeReferenceIdentifier should
be used for com:DocumentIdentifier. When the PrincipalDesignCategorydgn:PrincipalDesignCategory is set to "Current application" or "Main design" in a dgn:HagueRegistration, the value of com:InternationalRegistrationNumber
should be used for com:DocumentIdentifier. </xsd:documentation>
</xsd:annotation>