Re: RDFa Default Profile Management

On Feb 8, 2011, at 09:58 , Nathan wrote:

> Ivan Herman wrote:
>> On Feb 8, 2011, at 08:17 , Toby Inkster wrote:
>>> On Mon, 7 Feb 2011 14:10:54 +0100
>>> Ivan Herman <ivan@w3.org> wrote:
>>> 
>>>> There is nothing that disallows a library implementer to add a whole
>>>> bunch of additional prefixes if they want. But the default profile
>>>> gives you the minimum everybody can rely on!
>>> Well, actually there is something to stop them. If a consumer includes
>>> a default prefix mapping of something like:
>>> 
>>> 	"about" => "http://example.com/vocab/about#"
>>> 
>>> Then it will hit a compliance issue as soon as it sees:
>>> 
>>> 	<span rel="next" resource="about:blank">this is the last
>>> 	page</span> 
>> Why? I do not understand...
> 
> about: isn't an IANA registered URI scheme, however the browsers do use it, and "about:blank" is defined in HTML 5
> 
>  "if the resource is identified by the URL about:blank, then the resource is immediately available and consists of the empty string, with no metadata."
> 
> http://dev.w3.org/html5/spec/Overview.html#about:blank
> 
> AFAICT the rule only comes in to play, in HTML when a User Agent tries to "fetch" that URI though, say because it's in an @href.
> 
> Unsure if it's an issue, but it definitely has a "meaning" in html.

This is not an issue for RDFa, though.

Ivan


> 
> Best,
> 
> Nathan
> 
> 


----
Ivan Herman, W3C Semantic Web Activity Lead
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