Re: External Enumerations mechanism

On Apr 25, 2012, at 16:04 , jean delahousse wrote:

> Hello,
> Just to be sure, you say it is not possible to express this : 
>  <p vocab="" resource="#manu" typeof="Person wiki:Programmer"> .
> whith microdata as microdata does not support multiple types ?

Correct. It can, afaik, accept multiple types if they are on the same 'domain' (I do not remember how that is defined) but not like this. Remember that microdata does not differentiate between types and vocabularies; vocabularies are, essentially, established by the type being used.

You can, of course, add a separate <link> element with an explicit rdf:type.


> It is too bad because it exactly answers the needs a) to use high level classes inside to have a shared classification, b) to be able to use any external vocabularies to get a more detailed or more domain oriented description.
> Cheers
> Jean Delahousse
> 2012/4/25 Dan Brickley <>
> On 25 April 2012 02:17, Guha <> wrote:
> > After some discussion, etc., here is the next version of the proposal:
> >
> >  The canonical urls that recommends for use will the urls for the
> > entities on the reference sites (wikipedia, freebase, nist, etc.) When these
> > reference sites add new entities (such as South Sudan as a new country),
> > webmasters can immediately start using them.
> >
> >  In addition, to make the common use case much easier, will
> > provide documentation pages that list the entities (and their external
> > urls), along with the caveat that the external entity is the primary source.
> >
> >  How does this sound?
> I think this is heading in the right direction. I've updated
> accordingly,
> with links into the wiki history for the earlier draft and for this
> discussion.
> My update is a first-pass and there may be (conceptual or technical)
> remnants of the earlier design in there. We don't say anything about
> URLs for countries vs pages about those countries, or whether we
> expect HTML+Microdata (or RDFa, or whatever) at those URLs. I think
> some flexibility is appropriate at this stage.
> Daniel Dulitz notes (rightly) that the doc is currently a little
> unclear as to whether we yet handle the externally enumerated subtypes
> scenario. There are two syntax issues there: firstly that Microdata
> doesn't support multiple types, and seems unlikely to change.
> Secondly, when looking to the future and RDFa Lite usage, RDFa now
> comes "out of the box" with some prefix bindings for existing W3C
> vocabularies and for other commonly encountered general purpose RDF
> vocabularies. I have started a conversation with Ivan (cc:'d) about
> whether there might be scope to collaborate there.  This "RDFa initial
> context" list, see
> and background doc was
> based on crawler stats from Yahoo and Sindice. It doesn't currently
> include "bulk" vocabularies like e.g. DBpedia, but there might be
> some scope for doing so. The syntactic benefit is that RDFa Lite's
> 'typeof' attribute can take a space-separated list of types:
> So a simple description looks like this (from
> )
> <p vocab="" resource="#manu" typeof="Person">
>   My name is <span property="name">Manu Sporny</span>
>   and you can give me a ring via
>   <span property="telephone">1-800-555-0199</span>.
>   <img property="image" src="" />
> </p>
> Whereas if we wanted to say that Manu is in some other type too, eg. C
> programmer, we can drop in or
> (if the prefix is declared explicitly or via the W3C 'starter list'
> just wiki:Programmer, ... or some more precise URL that means 'C
> programmer'. Ideally Microdata would allow something like this too.
> In RDFa then, sub-type external enumerations would be <p
> vocab="" resource="#manu" typeof="Person
> wiki:Programmer"> ... how does that look?
> Dan
> -- 
> --------------------------------------------------------------------------------------------------------
> +33 6 01 22 48 55,, skype: jean.delahousse
> @jdelahousse, 

Ivan Herman, W3C Semantic Web Activity Lead
mobile: +31-641044153

Received on Wednesday, 25 April 2012 14:46:05 UTC