Meaning of recommended properties on Standards

[jakubklimek]

Motivation
GeoDCAT-AP 2.0.0 specifies recommended properties for Standards:

• description
• identifier
• reference register
• release date
• title
• type
• version

However, even in GeoDCAT-AP examples, the recommended properties are not used, e.g. Example 25:

<http://www.opengis.net/def/crs/OGC/1.3/CRS84> a dct:Standard ;
  dct:identifier "urn:ogc:def:crs:OGC:1.3:CRS84"^^xsd:anyURI ;
  dct:title "CRS84"@en ;
  dct:type <http://inspire.ec.europa.eu/glossary/SpatialReferenceSystem> ;
  skos:inScheme <http://www.opengis.net/def/crs/OGC> ;
  skos:prefLabel "CRS84"@en .

Questions

1. What is the meaning of recommended here? Should the properties be used with all standards mentioned in GeoDCAT-AP? e.g. with http://www.opengeospatial.org/standards/wms in the following example?

[] a dcat:DataService;
    dct:conformsTo <http://www.opengeospatial.org/standards/wms> .

2. Should they be used only for standards for which there are no URIs?
3. Is there a registry of standards in which the standards are documented using the recommended properties?

Possible proposals

1. Move recommended properties to optional properties for Standards

[jakubklimek]

Voting on this issue postponed to give the community more time to discuss it here in GitHub.

[jakubklimek]

Since no additional feedback was received, this is resolved in sync with #109 - all properties for supporting entities, including Standards, will be optional.