- From: Ed Summers <ehs@pobox.com>
- Date: Wed, 13 Feb 2013 11:29:05 -0500
- To: Lin Clark <lin.w.clark@gmail.com>
- Cc: whatwg@lists.whatwg.org
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@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@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
Received on Wednesday, 13 February 2013 16:29:34 UTC