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Re: Indicating main entity / primaryTopic - proposal to use 'schema.org/about'

From: Dan Brickley <danbri@google.com>
Date: Tue, 20 May 2014 18:01:04 +0100
Message-ID: <CAK-qy=54hBL5TpuVDPA+MR77=cSmFMm68q1OpVT8uVyoUKsDdw@mail.gmail.com>
To: Jason Douglas <jasondouglas@google.com>
Cc: W3C Web Schemas Task Force <public-vocabs@w3.org>
On 20 May 2014 17:30, Jason Douglas <jasondouglas@google.com> wrote:
> I think you buried the lede in the github link at the bottom.  :)
( https://gist.github.com/anonymous/cf7e24f6378b176aa010 )

Ok, let's jump into the markup. It does flush out some issues -


> In terms of markup would it be reasonable to do this?

Slight tweaks (discussing hashes and slashes with Dan Scott and
Stephane Corlosquet in IRC...):

 <html vocab="http://schema.org/">
   <head>
     <link property="about" href="#main_item"/>
   </head>
   <body>
     <div resource="#main_item" typeof="MusicEvent">
       ...
     </div>
   </body>
 </html>

(this adds a '/' in the @vocab url, and # within @resource attribute)

> and rely on an implicit WebPage subject?

Looks fine from RDFa point of view. Even though "implicit WebPage" is
a schema.org convention, generic RDFa 1.1 parsing would attach the
'about' property to the default base URL, which would be the page.

As for Microdata I'm not sure the best pattern, but this with more
RDFa-ish structure in the <head> might be bearable:

<html>
   <head>
     <link rel="http://schema.org/about" href="#main_item"/>
   </head>
   <body>
     <div id="main_item" itemscope itemtype="http://schema.org/MusicEvent">
       ...
     </div>
   </body>
 </html>


FWIW another everything in the body pattern that works for RDFa (but
dips into RDFa 1.1 beyond the Lite subset) is:

<div vocab="http://schema.org/" typeof="Person">
 <link rev="about" href=""/>
 <span property="name">John Smith</span>
</div>

Which brings me to another issue that's never far away - we have a lot
of ways of saying quite similar but different things(*):

<div vocab="http://schema.org/" typeof="Person">
 <link rel="url sameAs officialWebPage" rev="about" href=""/>
 <span property="name">John Smith</span>
</div>

At least this is pretty compact markup, but we owe the world an
account of how at least 'url', 'sameAs' and 'about' interact.

e.g. for any x, y where  x--sameAs-->y, is y--about-->x going to be true?

sameAs's definition: "URL of a reference Web page that unambiguously
indicates the item's identity. E.g. the URL of the item's Wikipedia
page, Freebase page, or official website." ... which covers the
official website use case.


Dan



(*) officialWebPage is used by Yandex e.g. see
http://help.yandex.com/webmaster/supported-schemas/review-car.xml but
similar ideas surfaced here in the social/profile/account discussion
Received on Tuesday, 20 May 2014 17:01:32 UTC

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