<https://www.omg.org/spec/NIEM-UML/>
<http://www.omg.org/techprocess/ab/SpecificationMetadata/specificationURL>
<https://www.omg.org/spec/NIEM-UML/About-NIEM-UML/>
<https://www.omg.org/spec/NIEM-UML/3.0/Beta1/>