Re: [dxwg] Must a DCAT profile validate against all of DCAT? (#430)

I agree that strictly defining conformance is not appropriate for DCAT2. Well to be more precise, I think the [current conformance section](https://w3c.github.io/dxwg/dcat/#conformance) is doing a good enough job for it.

In my reading this week, I however encountered a problem that I think no other document than the DCAT2 spec can address: the issue of determining what is "all of DCAT" (as per the title of this issue) for defining profiles and conformance. Namely my problem is with terms from external namespaces.
The paragraph [external terms in the intro](https://w3c.github.io/dxwg/dcat/#sotd) says
> conformance to DCAT (ยง 4. Conformance) concerns usage of only the terms in the DCAT namespace itself

[Section 4](https://w3c.github.io/dxwg/dcat/#conformance) includes the following sentences:

> The contents of all metadata fields [...] are expressed using the appropriate classes and properties from DCAT, except where no such class or property exists.

> Additional constraints in a profile MAY include [...] Sub-classes and sub-properties of the standard DCAT classes and properties; Classes and properties for additional metadata fields not covered in DCAT.

This leaves me quite puzzled, about how one should consider the external terms. It is indeed hard to understand that section 4 would consider that elements "from DCAT" or "standard DCAT classes and properties" would not include something like foaf:homepage. Otherwise this means that foaf:homepage is an "additional metadata field not covered in DCAT". And thus every specification that adds foaf:homepage to the core DCAT namespace would be a DCAT profile. But this means that the specification described in the DCAT2 CR is a profile of DCAT, not DCAT itself! This sound odd. So I'm concluding that for section 4 foaf:homepage is in DCAT. But that is at odds with the paragraph on external terms.

NB: I'm happy to move this to another, new issue if the raiser of this issue (@agreiner ) thinks it's out of scope.


-- 
GitHub Notification of comment by aisaac
Please view or discuss this issue at https://github.com/w3c/dxwg/issues/430#issuecomment-534035135 using your GitHub account

Received on Monday, 23 September 2019 10:02:00 UTC