Re: Property "geographic identifier" in LOCN (was: Re: ISA Core Location Vocabulary)

Apologies for my late reply, Raphaël.

About your question:

When this property was introduced in the vocab? Is it a mapping with a
> specific field from the INSPIRE schemas?
>

In INSPIRE, the notion of "geographic identifier" is defined in the Generic
Conceptual Model (GCM) [1] (Section 10.6, page 81), and it is based on the
ISO one (19109 & 19112). To summarise:
- Such ID can be either a "structured identifier" (e.g., a URI) or a
"linguistic name" (i.e., a geographical name), and, quoting [1], "may be
used in an INSPIRE application schema to reference LocationInstance objects
in a gazetteer".
- Such notion is used in the GCM schema for two attributes of class
LocationInstance, namely, @geographicIdentifier and
@alternativeGeographicIdentifier (you can see the relevant UML diagram at
[2])

So, to come to the point, one of the reasons of introducing in the LOCN
vocabulary a property for "geographic identifier" was to recommend the use
of rdfs:seeAlso for "alternative geographic identifiers". We didn't suggest
the use of owl:sameAs, because the point was that "alternative geographic
identifiers" are supposed to come from different datasets / gazetteers, so
rdfs:seeAlso is safer.

The idea was also to promote the use of URIs for geographic identifiers.
However, rdfs:seeAlso does not prevent, a priori, the use of other
"structured identifiers" or of a "linguistic name" - they just have to be
expressed as instances of specific classes. For instance:
- a "linguistic name" can be expressed by using an RDF version (to be
defined) of the INSPIRE Geographical Names data model [3,4] (the
alternative is of course to use locn:geographicName),
- for identifiers the same might be done by using, e.g., class
adms:Identifier [5].

Andrea

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[1]
http://inspire.jrc.ec.europa.eu/documents/Data_Specifications/D2.5_v3.4rc3.pdf
[2]
http://inspire-twg.jrc.ec.europa.eu/data-model/approved/r937/index.html?goto=3:1:1:7840
[3]
http://inspire-twg.jrc.ec.europa.eu/data-model/approved/r937/index.html?goto=2:8:2:7422
[4]
http://inspire.jrc.ec.europa.eu/documents/Data_Specifications/INSPIRE_DataSpecification_GN_v3.0.1.pdf
[5]http://www.w3.org/TR/vocab-adms/#identifier