W3C home > Mailing lists > Public > public-rdfa@w3.org > February 2009

Re: how to mark up a photo on the web

From: Steven Pemberton <steven.pemberton@cwi.nl>
Date: Mon, 23 Feb 2009 15:36:47 +0100
To: "Ben Adida" <ben@adida.net>, "public-rdfa@w3.org" <public-rdfa@w3.org>
Cc: semantic-web@w3.org
Message-ID: <op.ups6vll8smjzpq@acer3010>
>  <div about="./maddie.jpg">

Nitpick: just maddie.jpg (and below)

>     <h2 property="dc:title">Please</h2>
>     <img src="./maddie.jpg" />

Remember all the discussions we had about allowing @src to be a subject? A  
future simplification of RDFa can surely drop the rules about @src, simply  
because they will hardly ever be used in real life.

>     <a rel="license"
>        href="http://creativecommons.org/licenses/by-sa/3.0/">
>       <img alt="Creative Commons License" style="border-width:0"
> 	   src="http://i.creativecommons.org/l/by-sa/3.0/88x31.png"
> 	   /></a><br />

I would put these lines lower down to gather all the licence information  
in one place. Oh wait, it's there as well. Delete this then.

> 	   <em property="dc:description">Maddie begs for a treat.</em>
>            Tags: <span property="dc:subject">dog</span>, 
>                  <span property="dc:subject">cute</span>, 
>                  <span property="dc:subject">beg</span><br />

I was surprised to see dc:subject being used like this, but Dublin Core  
says "Typically, the subject will be represented using keywords, key  
phrases, or classification codes. Recommended best practice is to use a  
controlled vocabulary. To describe the spatial or temporal topic of the  
resource, use the Coverage element." so I guess I'm overruled!

> 	   Taken on <span property="dc:date" datatype="xsd:date"  
> content="2008-12-15">Dec. 15th</span>

dc:date looks reasonable, but I notice some people complaining.  
Interestingly the wording for dc:coverage seems to deal with both time and  
lat/long: "The spatial or temporal topic of the resource". "Spatial topic  
and spatial applicability may be a named place or a location specified by  
its geographic coordinates. Temporal topic may be a named period, date, or  
date range."

>            by <a rel="dc:creator" href="http://yergler.net/#me"><span  
> property="foaf:name">Nathan Yergler</span></a>.

No need for the span:

	by <a rel="dc:creator" href="http://yergler.net/#me"  
property="foaf:name">Nathan Yergler</a>.

> 	   (<span property="geo:latitude">57.64911</span>/<span  
> property="geo:longitude">10.40744</span>)

This smells of the primary-topic-of debate, the difference between the  
location of the photo, and the location of what the photo depicts. If the  
image were of a painting by Van Gogh would we expect the lat/long to tell  
us where it hangs, or of where it depicts?

> 	   <br />
>           This work by <a xmlns:cc="http://creativecommons.org/ns#"
> 	   
> href="http://labs.creativecommons.org/~nathan/image-rdfa/madeline.html"
> 	  property="cc:attributionName"	  rel="cc:attributionURL">Nathan R.  
> Yergler</a>

I don't like the link with text of someone's name leading to an image of  
his dog; I bet he doesn't either! The link to the dog should be around  
"This work". The href can be "", though you might prefer it not to be for  
didactic reasons, but it does explain the text "This work" better.  
Nathan's name should just be in a span.

>           is licensed under a
>                <a rel="license"
> 	           
> href="http://creativecommons.org/licenses/by-sa/3.0/">Creative Commons  
> Attribution-Share Alike 3.0 Unported License</a>.
>   </div>

Best wishes,

Steven
Received on Monday, 23 February 2009 14:37:06 GMT

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