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RE: Context Independent URI

From: Mike Dierken <mike@dataconcert.com>
Date: Mon, 22 Jul 2002 09:18:52 -0700
Message-ID: <2AE31649CF989F4FB354F6D95EB0CE6E5CEE4F@xmlfmail.xmlfund.com>
To: "'www-tag@w3.org'" <www-tag@w3.org>


FYI - there is a lot of work on the tel: URI scheme that deals with phone
network contexts (specifying what area code the number can validly be used
within, etc.).
It isn't the same as the context dependent issues you bring up, but it is
sort of related.

If you talk about URIs in general, you may need to measure your findings
against this specification one way or another.

http://www.ietf.org/rfc/rfc2806.txt



> -----Original Message-----
> From: Williams, Stuart [mailto:skw@hplb.hpl.hp.com] 
> Sent: Sunday, July 21, 2002 2:19 PM
> To: 'www-tag@w3.org'
> Subject: Context Independent URI
> 
> 
> 
> At the TAG telcon on 15th July [1] I was assigned the action 
> to draft a principle on context independent/globally scoped URI. 
> 
> Here's my first draft:
> 
> <principle>
> ContextIndependentURI: 
> A URI SHOULD denote the same resource or concept independent of the
> context(s) in which the URI is used. i.e. when used on 
> different occasions or by different users or in different 
> locations, a given URI SHOULD denote the same resource or 
> concept. </principle>
> 
> <rationale>
> Some URI schemes, such as file:, and some URI authority, such 
> as localhost
> eg: http://localhost/, can give rise to URI which, although 
> syntactically absolute URI, denote different resources or 
> concepts dependent on the context in which they are used. If 
> a given URI denotes multiple different resources or concepts 
> depending on context, then further information in addition to 
> the given URI is required to distinguish between resources 
> denoted by the same URI. This is a long standing principle of 
> Web Architecture [2].
> 
> [2] http://www.w3.org/DesignIssues/Axioms.html#unique
> </rationale>
> 
> <furtherDiscussion>
> All identifiers are in some sense relative to a namespace. On 
> the Web the outermost namespace is the set of all URI. A 
> given URI is relative to some URI scheme, and depending on 
> that scheme the URI assigned under that scheme may be 
> relative to some authority or subordinate namespace (eg. URN 
> namespaces).
> 
> So... I have tried to avoid using the term absolute to avoid 
> confusion with absolute and relative URI and tried to focus 
> the principle on the scope of the mapping from URI to 
> resource/concept.
> 
> It might be useful to discuss whether there are any 
> situations that locally scoped absolute URI are positively useful (eg:
> http://autoproxy/autoproxy/autoproxy) - or maybe one would 
> argue that this identifies the concept/resource of the "local 
> proxy configuration".
> 
> </furtherDiscussion>
> 
> Comments, feedback?
> 
> Regards
> 
> Stuart Williams.
> [1] http://www.w3.org/2002/07/15-tag-summary
> 
Received on Monday, 22 July 2002 12:19:36 GMT

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