- From: Ivan Herman <ivan@w3.org>
- Date: Wed, 13 Feb 2013 07:41:09 -0500
- To: Ed Summers <ehs@pobox.com>
- Cc: Richard Wallis <richard.wallis@oclc.org>, "public-schemabibex@w3.org" <public-schemabibex@w3.org>
On Feb 13, 2013, at 07:12 , Ed Summers <ehs@pobox.com> wrote: > On Wed, Feb 13, 2013 at 6:54 AM, Richard Wallis <richard.wallis@oclc.org> wrote: >> In principle I agree with you - it is a kludge of a solution and Microdata >> could be improved by the ability to support multiple type URIs. > > My reading of the HTML 5 Microdata spec is that multiple types are allowed: > > The itemtype attribute, if specified, must have a value that is an > unordered set of unique space-separated tokens that are > case-sensitive, each of which is a valid URL that is an absolute > URL, and all of which are defined to use the same vocabulary. This is the sticking point. If you use @itemtype with, say, a schema Type, then it is not allowed to add a type from another vocabulary. FWIW, the microdata->RDF mapping document[1] has been modified/extended due to the additionalType stuff; in practice, the generated RDF will include the rdf:type statements, too. Of course, this is of interest only if the client wants to use RDF. Ivan [1] http://www.w3.org/TR/microdata-rdf/ > The attribute's value must have at least one token. [1] > >> The original 'Library' extension proposal that accompanied the OCLC WorldCat >> linked data release last year, highlighted some of the carrier types >> (catalogued by libraries which contribute records to WorldCat) that were >> missing from Schema. I am confident that that proposal will be superseded >> by recommendations from this group. > > If memory serves it highlighted all of the carrier types, or at least > a lot more than I would have, which is something I will resist doing > in schema.org. If OCLC wants to publish a comprehensive list of > carrier types for use in microdata and RDFa that seems fine. But > baking all of that into schema.org is not palatable for me, especially > given the overlap with types that are already present. Is it too > difficult for us to itemize which types are not present in schema.org > that we need to have for expected use of bibliographic data? Can we > take lossless transformation of MARC to schema.org off the table? > > //Ed > > [1] http://www.whatwg.org/specs/web-apps/current-work/multipage/microdata.html#attr-itemtype > ---- Ivan Herman, W3C Semantic Web Activity Lead Home: http://www.w3.org/People/Ivan/ mobile: +31-641044153 FOAF: http://www.ivan-herman.net/foaf.rdf
Received on Wednesday, 13 February 2013 12:41:48 UTC