[whatwg] itemtypes from same vocabulary

[Lin Clark]

Sorry if it wasn't clear, at the time that those discussions took place,
only one itemtype could be used. Since then, the spec was changed to allow
multiple itemtypes from the same vocabulary.

However, both discussions also touch on the issue of using multiple
vocabularies in itemtype. For example, my response [1] in the first.

[1]
http://lists.w3.org/Archives/Public/public-whatwg-archive/2011Jun/0383.html


On Wed, Feb 13, 2013 at 11:29 AM, Ed Summers <ehs at pobox.com> wrote:

> Hi Lin,
>
> I'm confused because it looks like Microdata currently allows multiple
> itemtypes to be expressed:
>
> """
> 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. The
> attribute's value must have at least one token. [1]
> """
>
> I am seeking clarification about what is meant by 'same vocabulary',
> the rationale, and whether it can be relaxed.
>
> //Ed
>
> [1]
> http://www.whatwg.org/specs/web-apps/current-work/multipage/microdata.html#items
>
> On Wed, Feb 13, 2013 at 11:23 AM, Lin Clark <lin.w.clark at gmail.com> wrote:
> > Itemtype cannot reference different vocabs. Here are two relevant
> > discussions that I know of, one with Hixie and the other with the HTML
> Data
> > Task Force.
> >
> >
> http://lists.w3.org/Archives/Public/public-whatwg-archive/2011Jun/0364.html
> >
> http://lists.w3.org/Archives/Public/public-html-data-tf/2011Oct/0072.html
> >
> >
> > On Wed, Feb 13, 2013 at 11:18 AM, Ed Summers <ehs at pobox.com> wrote:
> >>
> >> Hi all,
> >>
> >> I am looking for some guidance about the use of multiple itemtypes in
> >> microdata [1], specifically the phrase "defined to use the same
> >> vocabulary" in:
> >>
> >> """
> >> The item types must all be types defined in applicable specifications
> >> and must all be defined to use the same vocabulary.
> >> """
> >>
> >> For example, does this mean that I can't say:
> >>
> >> <div itemscope itemtype="http://acme.com/Foo http://zenith.com/Bar">
> ...
> >> </div>
> >>
> >> The reason I ask is that there is some desire over in the schema.org
> >> community [2] to provide a mechanism for schema.org to be specialized.
> >> For example, in the case of an audiobook:
> >>
> >> <div itemscope itemtype="http://schema.org/Book
> >> http://www.productontology.org/id/Audiobook"> ... </div>
> >>
> >> The idea being not to overload schema.org with more vocabulary, and to
> >> let vocabularies grow a bit more organically. This schema.org group is
> >> currently thinking of using a one off property additionalType that
> >> would be used like so:
> >>
> >> <div itemscope itemtype="http://schema.org/Book">
> >>   <link itemprop="additionalType"
> >> href="http://www.productontology.org/id/Audiobook">
> >>   ...
> >> </div>
> >>
> >> I personally find this to be kind of distasteful since it replicates
> >> the mechanics that microdata's itemtype already offers.
> >>
> >> So, my question: is it the case that itemtype cannot reference types
> >> in different vocabularies like the example above? If so, I'm curious
> >> to know what the rationale was, and if perhaps it could be relaxed.
> >>
> >> //Ed
> >>
> >> [1]
> >>
> http://www.whatwg.org/specs/web-apps/current-work/multipage/microdata.html#items
> >> [2]
> >>
> http://lists.w3.org/Archives/Public/public-schemabibex/2013Feb/0000.html
> >
> >
> >
> >
> > --
> > Lin Clark
> > Drupal Consultant
> >
> > lin-clark.com
> > twitter.com/linclark
>



-- 
Lin Clark
Drupal Consultant

lin-clark.com
twitter.com/linclark