-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Am 05.08.2014 20:18, schrieb Denenberg, Ray: > Thomas Berger said: > “…except that (1) and (3) must allow for multiple values,” (string identifier and URI form) > > Seems to me this is asking for trouble (matching the string with the URI). > Why not instead provide multiple bf:IdentifierDescriptor resources (and declare them > equivalent)? In your example <http://example.com/xyz/book1> a bf:Instance ; <http://example.com/xyz/identifiers/book1/identifier1> a bf:IdentifierDescriptor ; bf:identifierScheme <http://id.loc.gov/vocabulary/identifiers/isbn> ; bf:identifierValue "9780099483793" ; bf:uriFormOfIdentifier “urn:isbn:9780099483793”. you provieded an arbitrary string version of a certain ISBN. And one of many possible equivalent URIs by RFC-3187 (actually not, as since Juha pointed out the urn:isbn scheme has not yet been extended to ISBN-13). And I provided some more equivalent forms for the identifier manifest on your book: <http://example.com/xyz/identifiers/book1/identifier1> bf:identifierValue "978-0-09-948379-3", "0-09-948379-3"; bf:uriFormOfIdentifier "URN:ISBN:0-09-948379-3". and of course there is "0099483793" and what we find imprinted in most english language publications, namely "978 0 09 948379 3", and "0 09 948379 3" (unfortunate example since the check digits of the ISBN-10 and ISBN-13 forms coincide). And of course there are representations prefixed by the string "ISBN ". Most of us will probably agree that the dashed, blanked and undelimited forms are just notational variants of each other. Additionally my point of view is that also "978-0-09-948379-3" and "0-09-948379-3" are just notational variants of /one/ ISBN (I have been referring to them as "abstract identifiers" in previous messages, please compare this with the distinction between "value space" and "lexical space" e.g. in the W3C XML Schema Datatypes document (< http://www.w3.org/TR/xmlschema-2/ >)). So for me the bf:IdentifierDescriptor as a resource would correspond to a distinct element of the /value space/ of the identifier system defined by the bf:identifierScheme and which element this is would be indicated by the bf:identifierValue literal residing in the lexical space for that identifier. If we had an XSD ISBN datatype the typed literals "978-0-09-948379-3" and "0-09-948379-3" would be the same anyway, so it would be nonsense to state more than one of them. Using the appropriate datatype also would obliviate the chore of explicitly naming the identifierScheme and we then could completely dispense the bf:identifierDescriptor and remain with <http://example.com/xyz/book1> a bf:Instance ; bf:identifier "978-0-09-948379-3"^^xsd:ISBNtype . Defining individual datatypes for any odd identifier system however seems not feasible, therefore we are sticking to plain string literals for the identifierValues and I see no harm to supply one bf:IdentifierDescriptor with several bf:identifierValues, especially since we usually denote (or transcribe) the ISBN-10 and its equivalent ISBN-13 within any description: Keeping equivalent ISBNs syntactically together helps keeping non-equivalent ISBNs (for print and eBook and the like) apart, I think. In an earlier message I proposed to set up with each "registered" identifierScheme an auxiliary bibframe address space for that system, providing "common" lexical values for the identifiers. so I could state <http://example.com/xyz/identifiers/book1/identifier1> owl:sameAs <http://bibframe.org/registry/isbn/978-0-09-948379-3> and this actionable URI could pull in <http://bibframe.org/registry/isbn/978-0-09-948379-3> a bf:IdentifierDescriptor ; bf:identifierScheme <http://id.loc.gov/vocabulary/identifiers/isbn> ; bf:identifierValue "9780099483793", "0099483793", "978-0-09-948379-3", "0-09-948379-3", "978 0 09 948379 3", "0 09 948379 3" ; bf:uriFormOfIdentifier “urn:isbn:9780099483793”, “URN:ISBN:0-09-948379-3”. and so on: A script simply would expand the identifier extracted from the URN and expand it to certain well known forms. (Of course the same content would be delivered when resolving <http://bibframe.org/registry/isbn/0-09-948379-3> or <http://bibframe.org/registry/isbn/9780099483793>: I'm not proposing some covert normalization of the permitted lexical values by distinguishing some URIs over others. Using that bibframe service infrastructure in a sense one could emulate what the hypothetical XSD datatype could provide: <http://example.com/xyz/book1> a bf:Instance ; bf:identifier <http://bibframe.org/registry/isbn/978-0-09-948379-3>; (I just have to remember that for accessing the actual values I have either to retrieve bf:identifierValues from the URI given or extract them from the URI with non-RDF tools) %-- As for the equivalence of bf:identifierValue and bf:uriFormOfIdentifier I'm not certain: RFC-3187 seems to state (in the language of 2003) that there is a transformation from ISBN value space to URI space and that apart from URI equivalence rules there are equivalence rules specific to URN:ISBN URIs. These are the common equivalences implemented by ignoring dashes, but I'm not sure about blanks and prefixes like "ISBN ". So it is probably best to think of independent sets of equivalence rules for bf:identifierValue s and bf:uriFormOfIdentifier s for any given scheme. viele Gruesse Thomas Berger -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iJwEAQECAAYFAlPhST8ACgkQYhMlmJ6W47ODlAP+MeQAjEv9A7qenHL24ePG31OP JJ/O79gPsEqw1HyvSuxKC3ARk3pAZ1SGFRd9RAueXVJP6ZkmWc38oCZ2cEEfZNiS zLq5DEKiXSOyzkfOCftsE4LsyllZnI8lAZ+xySsVFCP0jN9BvGzxPI0C23kVqj94 6G4slkSGyRFNqZy71I0= =UK8b -----END PGP SIGNATURE-----