change `canonicalURI` to DatatypeProperty

[VladimirAlexiev]

This one should be changed to a DatatypeProperty because it applies to instances not ontology terms:

era:canonicalURI rdf:type owl:AnnotationProperty ;
                 rdfs:range xsd:anyURI ;
                 rdfs:domain era:InfrastructureObject .

[VladimirAlexiev]

era:hashSource rdf:type owl:AnnotationProperty ;
               rdfs:comment "This property indicates for each infrastructure element, the source, i.e. the identifier  or key that was input to the hash function in order to generate the hash value that is part of the hash URI."@en ;
               rdfs:label "Hash source"@en ;
               rdfs:range xsd:string ;
               rdfs:domain era:InfrastructureObject .

Conversely: I doubt that this prop applies to instances? I think that for each class of infrastructure element, the hash sources are the same?

• If so, change the domain to owl:Class
• If not so, change it to a DatatypeProperty

[Interoperable-data]

era:canonicalURI is meant to annotate objects (in this case mainly infrastructure objects) with the so call canonical. We might probably want to open the domain to rdfs:Resource. Would that solve this issue?

[VladimirAlexiev]

I don't know why I was confused the domain should be Class. Keep the domain as InfrastructureObject.

But what is the range? It says "identifier or key": if this field is RDFized (as it should be!) then

• change the type to ObjectProperty
• change the range to rdf:Property
• ensure that the values are ERA property URLs, not strings

Can you give some example values?