Re: Property "geographic identifier" in LOCN

-->> [ to make my point clear ]

> Hum, org:identifier is a subProperty of skos:notation ... which is an instance of owl:DatatypeProperty ... which contradicts the fact that we want this id to be sometimes a URI, isn't it?

 org:identifier is a a owl:DatatypeProperty, rdf:Property, see http://www.w3.org/ns/org#identifier.
And the org:Organization class contains this statement [ owl:hasKey (org:identifier) ; ]

So we can similarly say for locn, as you suggested something like: 

locn:identifier a owl:DatatypeProperty, rdf:Property ;
	rdfs:range [a rdfs:Datatype ; 
		owl:unionOf (xsd:URI rdfs:Literal) .] ;

Does it make sense?

And add to the appropriate class in locn vocab an axiom like the one stated in org like:
locn:aClass owl:hasKey (locn:identifier) ;

WDYT?

Best,

Ghislain