odrl:uid leaf node

@prefix odrl: <http://www.w3.org/ns/odrl/2/> .
@prefix owl: <http://www.w3.org/2002/07/owl#> .
@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
@prefix skos: <http://www.w3.org/2004/02/skos/core#> .

odrl:uid a rdf:Property,
        skos:Concept ;
    rdfs:label "Unique Identifier"@en ;
    rdfs:domain [ a owl:Class ;
            owl:unionOf ( odrl:Policy odrl:Asset odrl:Rule odrl:Party odrl:Constraint odrl:LogicalConstraint ) ] ;
    rdfs:isDefinedBy odrl: ;
    skos:definition "An unambiguous identifier"@en ;
    skos:note "Used by the Policy, Rule, Asset, Party, Constraint, and Logical Constraint Classes."@en .