Issuer control of granularity and decomposability of claims

[stonematt]

In use case E.1 Digital Transcript (https://opencreds.github.io/vc-use-cases/#education), Joleen is spearheading the concept of a 'extended transcript' - My question is about the "basic transcript" - and how it's a model for any issuer tracking collections of evidence that may or may not be in a hierarchy.

In the simple university case, there is a hierarchy of achievements from coursework -> exams (grade) -> course completion -> degree. In general, issues decide how their claims can be represented in the marketplace. Focusing on the top 2 levels for a moment.

A university issuers, issues a VC for the "degree" with course completion as evidence, as a result:

1. Holder can share all data in the claim
2. Holder can share only the degree w/out evidence (is this a new claim w/out evidence?)
3. Holder cannot decompose the VC and share only 1 of the courses

-- Is Item 2 above the sort of thing we envision in 4.2 Assert Claim (https://opencreds.github.io/vc-use-cases/#assert-claim) where the holder can restrict the amount of information exposed? -- Can the university require the full detail of the evidence anytime the claim is used? -- If the exam was a distinct VC that included both score and grade as attributes, would we expect the issuer to be a able to mandate one as optional (like score) and one required (like grade)? This implies that issuer could mandate both attributes as required, thus restricting what the Holder can withhold.