Inconsistency in `issued`/`modified` properties.

[ifokkema]

According to the specs, the FDP endpoint requires (amongst others) the following two properties:

Ontology	Property name	Datatype	Cardinality
FDP Ontology	fdp-o:metadataIssued	xsd:dateTime	1
FDP Ontology	fdp-o:metadataModified	xsd:dateTime	1

However, the specs of the catalog mention the following four properties:

Ontology	Property name	Datatype	Cardinality
DC terms	dct:issued	DateTime	0..1
DC terms	dct:modified	DateTime	0..1
FDP Ontology	fdp-o:metadataIssued	xsd:dateTime	1
FDP Ontology	fdp-o:metadataModified	xsd:dateTime	1

It seems to me that this is redundant? I've checked two example FDPs, and they do implement both the dct as well as the fdp properties for catalogs, even though the values are the same. Rajaram's example GitHub FDP only uses the fdp fields for the catalog. I'll skip the dct fields in my implementation as well, which is allowed according to the specs, but I thought I'd report this regardless.

[luizbonino]

Hi Ivo, the difference between the act:issued/modified and fdp-o:metadataIssued/metadataModified properties is that the former properties are about the entity being described (e.g., Dataset, Catalog, DataService, etc.) and the latter refer to information about the metadata record, i.e., metadata about the metadata. This is normally automatic entered by the FDP reference implementation.

We are planning to modify this in the upcoming versions to have more explicitly the metadata record and the meta-metadata record.