I’m very supportive of the authorities proposal’s attempt to decouple authorities from the entities they describe.
For example: https://viaf.org/viaf/36997809/rdf.xml has a URI for the document ("http://viaf.org/viaf/36997809/“) and another for Carl Sagan himself ("http://viaf.org/viaf/36997809”, without the trailing slash). The Person URI has sameAs assertions with both authorities and entities modeled as persons.
Re:Roles, I’m a little confused about semantics of the role proposal,
That bf:Contributor has a related agent. Is the bf:Contributor really more of a Contribution, like a PROV Activity (http://www.w3.org/TR/prov-o/)? If so, the proposal makes semantic sense, and I would just recommend naming bf:Contributor to bf:Contribution or just using PROV activity.
Re: the Identifiers proposal, Karen has said this before, but we shouldn’t conflate the role of URIs with string identifiers. When I read the Authorities proposal, I interpret bf:identifiedBy as having the semantics:
<some thing> <is identified through an authority> <some authority resource> .
**But** the identifier proposal says the bf:identifiedBy property is for an identifier string.
That’s very different. I would recommend we be able to say the following through different properties:
<some bf:Resource> <is described by an authority> <some authority resource> .
<some authority resource> <is identified by an identifier> <some string identifier> .