doi: and isbn: schemes are not HTTP-dereferenceable. But it does not
mean they do not form valid URIs, in RDF or otherwise.

https://www.w3.org/TR/uri-clarification/

On Tue, Feb 19, 2019 at 5:09 PM Young,Jeff (OR) <[log in to unmask]> wrote:
>
> These unresolvable URI schemes are from the days when web standards didn’t support http URIs for things that weren’t web resources. That changed with httpRange-14 (2005), which officially allowed http URIs to be used to identify anything, enabling linked data (2006).
>
>
>
> The old way of defining/registering URI schemes that don’t have a corresponding protocol lost their value as a solution.
>
>
>
> Jefef
>
>
>
> From: Bibliographic Framework Transition Initiative Forum <[log in to unmask]> on behalf of Martynas Jusevičius <[log in to unmask]>
> Reply-To: Bibliographic Framework Transition Initiative Forum <[log in to unmask]>
> Date: Tuesday, February 19, 2019 at 10:59 AM
> To: "[log in to unmask]" <[log in to unmask]>
> Subject: Re: [BIBFRAME] When a bf:Identifier is a URI
>
>
>
> doi: and isbn: are both URN schemes, as far as I know.
>
> For example
>
> "urn:isbn:0-486-27557-4 "^^xsd:anyURI
>
> On Tue, 19 Feb 2019 at 16.52, Tim Thompson <[log in to unmask]> wrote:
>
> Thanks, Jeff--I was just about to point to the Wikidata approach as well. Isolating the uniquely identifying component from the IRI allows for greater flexibility and supports persistence: a formatter URL can be supplied (and potentially changed when needed) to dereference the identifier as an IRI and potentially include that in serialized output [1].
>
>
>
> Tim
>
>
>
> [1] https://www.wikidata.org/wiki/Property:P244#P1921
>
>
>
>
>
> --
> Tim A. Thompson
> Discovery Metadata Librarian
> Yale University Library
>
>
>
>
>
> On Tue, Feb 19, 2019 at 10:39 AM Young,Jeff (OR) <[log in to unmask]> wrote:
>
> I like how Wikidata deals with this in their RDF. Each identifier scheme gets its own property, which can then be described in various ways. For example:
>
>
>
> https://www.wikidata.org/wiki/Property:P244
>
>
>
> When you go to use that property as an external ID on items, which allows you to elaborate on that specific identifier using qualifiers, such as here:
>
>
>
> https://www.wikidata.org/wiki/Q963044#P434
>
>
>
> Jeff
>
>
>
> From: Bibliographic Framework Transition Initiative Forum <[log in to unmask]> on behalf of Simeon Warner <[log in to unmask]>
> Reply-To: Bibliographic Framework Transition Initiative Forum <[log in to unmask]>
> Date: Tuesday, February 19, 2019 at 10:24 AM
> To: "[log in to unmask]" <[log in to unmask]>
> Subject: Re: [BIBFRAME] When a bf:Identifier is a URI
>
>
>
> I agree with Lars on both counts. An unquoted URI in RDF does not stand
> for the identifier, it stands for the resource. Thus, ugly as it is,
> there is no option except using a literal. One might paraphrase:
>
> "The first rule of identifier club is that there is no way to talk about
> identifiers"
>
> Cheers,
> Simeon
>
>
> On 2/19/19 5:32 AM, Svensson, Lars wrote:
> > On Tuesday, February 19, 2019 9:49 AM, Adrian Pohl wrote:
> >
> >> On 19.02.19 04:03, Dan Scott wrote:
> >>
> >>> In a linked data context, I think that forcing a URI to be
> >>> represented as a literal (with a blank node as a bonus), instead of as
> >>> the URI it is, is an anti-pattern.
> >>
> >> I agree, but as I pointed out in the last email I also think that it is
> >> bad practice to use an URI when you are talking _about_ the URI (like it
> >> is bad practice to not add quotations when you are talking about a word
> >> in a written sentence).
> >
> > I tend to agree with Adrian here: We're talking about the identifier as a sequence of characters.
> >
> >> But there is a third option, we should definitely consider: In my
> >> opinion the best approach is to only use non-URI identifiers in a
> >> bf:identifiedBy statement so that the question does not come up. In the
> >> case that you have different URIs denoting the same resource it probably
> >> is best practice to use schema:sameAs or something similar to state that
> >> those URIs refer to the same thing.
> >
> > Here I tend to disagree with Adrian: We should not limit ourselves to non-URI identifiers.
> >
> > I'm also not quite happy with the use of schema:URL (what if we use IRIs?). My preferred pattern would be to use dct:type to say what kind of identifier it is and have a set of skos:Concepts to represent the identifier types. (I know, the definition of dct:type says that the rdfs:range is rdfs:Class, but I _think_ that the DCMI Usage Board currently is working on relaxing that to
> >
> > dct:type a rdf:Property ;
> > schema:rangeIncludes rdfs:Class .
> > ) [1].
> >
> > That way we'd get:
> >
> > @prefix bf: <http://id.loc.gov/ontologies/bibframe/> .
> > @prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
> > @prefix dct: <http://purl.org/dc/terms/> .
> > @prefix skos: <http://www.w3.org/2004/02/skos/core#> .
> >
> > <http://example.org/2335409#Work> a bf:Text, bf:Work ;
> > bf:identifiedBy [ a bf:Identifier ;
> > dct:type bf:URI ;
> > rdf:value "http://worldcat.org/entity/work/id/638612"
> > ] .
> >
> > bf:URI a skos:Concept .
> >
> > [1] https://github.com/dcmi/usage/blob/master/minutes/2018/2018-11-20.dcub-decisions.md
> >
> > Best,
> >
> > Lars
> >