Create the SHACL Profiling Document

[YoucTagh]

A comment from @nicholascar in #216

Just popping in here to say that the scope of SHACL Profiling needs to be determined shortly as the SHACL WG considers Phase 2 Deliverables, so we need to start formalizing the ideas we have for this work.

We don't yet have a shacl-profiling document in the repository, so this will need to be added shortly and then we can start to put in draft section headings.

The proposed editors for this Deliverable are as per #217 - @siwerner, @betehess, @YoucTagh with me as fallback editor - so we can lean on then now to get things started there.

[ajnelson-nist]

I know we'd discussed this on a working-group call a few weeks ago, but I think we immediately resumed confusion on this topic.

There are several understandings of the term "Profile" that members of the group bring. Which of these will apply in the SHACL Profiling document?

• OWL 2 has a document devoted to "Profiles" that lists various restrictions on OWL syntax in order to stay within certain logic spaces. "Profiles" include EL, QL, RL; each of those falls under OWL 2 DL, but Primer Sections 9 and 10 seem to not designate DL or its less-restricted parent rule set FULL to be profiles. In any case, OWL has at least the three profiles EL, QL, and RL.
  • I think some of the use cases for Node Expressions has encouraged some discussion of "Profiles" for SHACL based on performance guarantees, similar to OWL's notion of "Profile."
  • PROF doesn't mention this OWL document when it describes OWL in related work.
• PROF's "Profile" notion seems more general. I'm not currently much experienced with PROF, but saw some snippets from related work that help me understand a bit:

  (Related: DCAT) PROF borrows its main structures from DCAT in that PROF's prof:Profile & prof:ResourceDescriptor classes parallel DCAT's dcat:Dataset & dcat:Distribution classes.
  (Related: DCAT) The main subject that differentiates PROF from DCAT is that PROF specifically addresses the notion of conformance – of profiles to specifications or other profiles ...

So, my understanding of "Profile" as SHACL intends to use it is it's PROF's "Profile," and OWL's notion of "Profile" happens to be a narrower, but still compatible, notion consistent with PROF's.

Did I get that right? Should some description of these various definitions be included in #335 , or in a later PR once #335 gets the document stub in place?