I think the following constraint types shouldn’t be checked on qualifiers and references:
- symmetric (now open for discussion on T175594)
- inverse (now open for discussion on T175594)
- allowed qualifiers
- mandatory qualifiers
- type
I’ll also limit constraint checks for the following types to statements for now, because their implementation for other contexts is not trivial (see linked tasks):
- distinct values: T175561
- conflicts with: T175562
- item requires claim: T175562
- difference within range: T175565
- single value: T175566
- multi value: T175566
Which leaves the following constraint types to be checked on qualifiers and references immediately:
- Commons link
- format
- one of
- used as qualifier (and, once implemented, used as reference)
- range
- target requires claim
- value type