[whatwg] Trying to work out the problems solved by RDFa

Charles McCathieNevile chaals at opera.com
Sun Jan 4 16:04:54 PST 2009

On Mon, 05 Jan 2009 01:21:33 +1100, Henri Sivonen <hsivonen at iki.fi> wrote:
> On Jan 2, 2009, at 14:01, Benjamin Hawkes-Lewis wrote:
>> On 2/1/09 10:38, Henri Sivonen wrote:

>>> Is the problem in the case of recipes that the provider of the page
>>> navigation around the recipe is unwilling to license the navigation  
>>> bits under the same license as the content proper?
>> I thought Toby's example was that each recipe on the page needed a  
>> different licence, rather than a distinction between the main content  
>> area and the navigation.
> Oh. That can be solved by giving each recipe its own URI & HTML page and  
> scraping those pages instead of summary pages that might contain  
> multiple recipes.

Sure. In which case the problem becomes "doing mashups where data needs to  
have different metadata associated is impossible", so the requirement is  
"enable mashups to carry different metadata about bits of the content that  
are from different sources.

A use case for this:

There are mapping organisations and data producers and people who take  
photos, and each may place different policies. Being able to keep that  
policy information helps people with further mashups avoiding violating a  

For example, if GreatMaps.com has a public domain policy on their maps,  
CoolFotos.org has a policy that you can use data other than images for  
non-commercial purposes, and Johan Ichikawa has a photo there of my  
brother's café, which he has licensed as "must pay money", then it would  
be reasonable for me to copy the map and put it in a brochure for the  
café, but not to copy the data and photo from CoolFotos. On the other  
hand, if I am producing a non-commercial guide to cafés in Melbourne, I  
can add the map and the location of the cafe photo, but not the photo  

Another use case:
My wife wants to publish her papers online. She includes an abstract of  
each one in a page, but because they are under different copyright rules,  
she needs to clarify what the rules are. A harvester such as the Open  
Access project can actually collect and index some of them with no  
problem, but may not be allowed to index others. Meanwhile, a human finds  
it more useful to see the abstracts on a page than have to guess from a  
bunch of titles whether to look at each abstract.



Charles McCathieNevile  Opera Software, Standards Group
     je parle français -- hablo español -- jeg lærer norsk
http://my.opera.com/chaals       Try Opera: http://www.opera.com

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