Best way to define profile of DCAT ?

Hi,

I am not sure this is the right mailing list to ask this question as
the  Government
Linked Data WG mailing list is closed now. I have a question about the
creation of DCAT profiles.
The DCAT specification defines a number of properties in the specification
and uses extensively properties from Dublin Core. However the DCAT ontology
document does not contain any reference to these external properties and
does not define any constraints on them (cardinality or domain). To know
which properties needs to be used, profiles such as DCAT-AP are defined,
but again it is not clear why they do no use OWL to impose constraints on
cardinality or domain. While I understand this gives a lot of flexibility
to the standard, it makes also difficult to build application from the
ontology without knowing which properties to use when you want to capture
metadata about datasets for example.

Could anyone explain why this design choice has been done and what is the
best way to write a profile for DCAT to indicate which properties to use
(should I use OWL with cardinality or just copy definition of properties
(DC Properties) without importing the ontology) ? Any other alternative
approaches ?

Thanks
Stephane Fellah
Chief Knowledge Scientist