Reserving a namespace for citygml owl/rdf

[nataschake]

(Vote @rob-metalinkage @avillar @VladimirAlexiev @ar-chad @svilenvarbanov2019 )
We talked about

• https://www.opengis.net/ont/citygml/3.0/rdf
• https://www.opengis.net/ont/citygml/3.0/owl
  separation (e.g. in light of alternatives(RDFS style) and 1.2(OWL style), but we could leave
• https://www.opengis.net/ont/citygml/ assuming the only one presentation of CityGML 3.0 will be used broadly.

[VladimirAlexiev]

I vote for https://www.opengis.net/ont/citygml/.
IMHO having RDFS vs OWL versions of the ontology will just lead to confusion...

[nataschake]

I only think if we can keep the version of CityGML?

[rob-metalinkage]

I'd rather have one namespace - not separate versions - but if we have a major semantic incompatibility we need to understand how to handle it. I'd love to have Ontotext's view on the most sustainable approach to versioning...

[nataschake]

I will use https://www.opengis.net/ont/citygml/3.0/building/ and all of the kind.

Initially the namespaces are declared as e.g., http://www.opengis.net/citygml/building/2.0, so the version is in the namespace URI.

[nataschake]

Again, we follow "slash-not-hash" way, so all the namespaces that are now like:
https://www.opengis.net/ont/citygml/3.0/building# will be
https://www.opengis.net/ont/citygml/3.0/building/

[VladimirAlexiev]

@nataschake Using version numbers in ontology term URLs makes them unstable.
People want to use the latest version, so if the version is changed, they need to do database migrations.
This causes pain, eg see in Electrical CIM:

• Express links to old ontology term URLs Sveino/Inst4CIM-KG#70
• Align NC instance file to both CGMES 2.4 and CGMES 3.0 Sveino/Inst4CIM-KG#123

We can use owl:versionIRI, versionInfo to capture the version. Eg:

@prefix citygml: <https://www.opengis.net/ont/citygml/>.

citygml: a owl:Ontology;
  owl:versionIRI <https://www.opengis.net/ont/citygml/3.0.0/>;
  owl:versionInfo "3.0.0"
  ...

[nataschake]

version info added to CityOWL.ttl