deleted in UML:
- ddi3_2Identifier (identifier of the DDI 3.2 representation)
- ddi3_1Identifier (identifier of the DDI 3.1 representation)
- ddi3_0Identifier (identifier of the DDI 3.0 representation)
- ddi2_5Identifier (identifier of the DDI 2.5 representation)
- ddi2_1Identifier (identifier of the DDI 2.1 representation)

added to UML:
- adms:identifier (domain: rdfs:Resource, range: adms:Identifier)
- adms:Identifier