[whatwg] Annotating structured data that HTML has no semantics for

[Philip Taylor]

On Mon, May 11, 2009 at 6:15 PM, Giovanni Gentili
<giovanni.gentili at gmail.com> wrote:
> * a user (or groups of users) wants to annotate
> items present on a generic web page with
> additional properties in a certain vocabulary.
> for example Joe wants to gather in a blog
> a series of personal annotation to movies
> (or other type of items) present in imdb.com.
>
> [...]
>
> this option require that @subject accept:
>
> 1) ID of an element with an item attribute, in the same Document
> or
> 2) valid URL of an element with an item attribute elsewhere in the web
> or
> 3) a valid URL (ithe item is the referred document or fragment)

For the RDF output, you can use <link property="about"
href="http://subject/"> to create triples whose subject is a URL. (I
believe in general you can also do:
  <meta item id="n0">
  <link subject="n0" property="about" href="http://subject/">
  <link subject="n0" property="http://predicate1/" href="http://object1/">
  <meta subject="n0" property="http://predicate2/" content="object2">
to represent arbitrary RDF triples.)

I don't think it would make sense for @subject to be a URL when
generating JSON output, because there wouldn't be anywhere to
represent that URL in the output structure. But there could be a
convention that properties called "about" indicate the URLs that the
item applies to, and then it would work with exactly the same markup
as the RDF case.

-- 
Philip Taylor
excors at gmail.com