This issue has been reported by Antonio Rotundo.
Draft 6 of the GeoDCAT-AP specification, in its Annex II.8, proposes to use the property dcat:theme for the INSPIRE metadata element "Keyword value" (only in case that the controlled vocabulary for the keywords is the one of the INSPIRE spatial data themes). However, it is not conformant to the requirement given by DCAT-AP in its Annex II.
Antonio proposes to move the property dcat:theme to the extended profile in order to use the codelist in INSPIRE registry (proposed even as controlled vocabulary in chapter 6) to express the keywords.
This issue has been clarified with the DCAT-AP WG. The DCAT-AP recommendation is not exclusive, i.e. dcat:theme must be used with the theme vocabulary in Annex II of the DCAT-AP spec., but this does not exclude the possibility of having other instances of dcat:theme using other vocabularies/thesauri. There is a statement in the Conformance section which allows additional assertions with dcat:theme that use other theme vocabularies (which then may or may not be understood by data receiver):
For the properties listed in the table in section 5, the associated controlled vocabularies MUST be used. Additional controlled vocabularies MAY be used.
- GeoDCAT-AP: controlled vocabulary for marine regions
- GeoDCAT-AP: Controlled vocabulary for location information
- GeoDCAT-AP: Controlled vocabulary for discipline
- GeoDCAT-AP: Controlled vocabulary for spatial resolution
- GeoDCAT-AP: Controlled vocabulary for spatial representation type
- GeoDCAT-AP: Keyword controlled vocabulary
- GeoDCAT-AP: Controlled vocabularies for frequencies