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RE: Dates in URIs?

From: Schleiff, Marty <marty.schleiff@boeing.com>
Date: Fri, 10 Nov 2006 07:30:36 -0800
Message-ID: <2C1C6A07EEDCB14ABBACAC793BF8BE9E02E96CC2@XCH-NW-6V2.nw.nos.boeing.com>
To: "Williams, Stuart \(HP Labs, Bristol\)" <skw@hp.com>, "Renato Iannella" <renato@nicta.com.au>, <noah_mendelsohn@us.ibm.com>, "John Cowan" <cowan@ccil.org>
Cc: <www-tag@w3.org>

Hi Stuart (& All),

Boy was I ever misunderstood!!! When I responded to your question 'What
on earth elevated these character sequences to the status of "metadata"
about anything?' I was trying to agree with you by pointing out that the
Finding (which should be clarifying the use of metadata) seems to muddy
the topic by elevating character sequences like "chicago" and
"your-city-name-here" to the status of metadata. I think the Finding
spends way too much time on stuff that arguably isn't metadata, or at
least not "usable metadata", and doesn't at all explore how to make
metadata usable. By usable I mean that explicit provisions are made for
carrying additional information, with the explicit intent that the
information be recoverable by inspection of the URI (sound familiar?:^).

The Finding does say, "Assignment authorities may publish specifications
detailing the structure and semantics of the URIs they assign", which
could result in usable metadata. However, the Finding does not explore
how to express those specifications in a meaningful way, how to
publish/find such specifications, or any examples of URIs including
structured and semantical metadata. 

Marty.Schleiff@boeing.com; CISSP
Associate Technical Fellow - Cyber Identity Specialist
Computing Security Infrastructure
(206) 679-5933
 

> -----Original Message-----
> From: Williams, Stuart (HP Labs, Bristol) [mailto:skw@hp.com] 
> Sent: Friday, November 10, 2006 2:09 AM
> To: Schleiff, Marty; Renato Iannella; 
> noah_mendelsohn@us.ibm.com; John Cowan
> Cc: www-tag@w3.org
> Subject: RE: Dates in URIs?
> 
> Marty
> 
> > From the first paragraph of the introduction: "Such metadata might 
> > include the title of a document, the creation date of the resource, 
> > the MIME media type that is likely to be returned by an HTTP GET, a 
> > digital signature usable to verify the integrity or 
> authorship of the 
> > resource content, or hints about URI assignment policies that would 
> > allow one to guess the URIs for related resources."
> 
> I raised comments on exactly that paragraph with Noah [1] 
> particularly:
> 
> From [2]:
> 
> <quote>
> > > "Many URI schemes offer a flexible structure that can also be used
> to 
> > > carry additional information, called metadata, about the 
> resource."
> > 
> > Stuart's comment:
> > 
> > > Do you have an example of such a scheme.
> > > I can't think of any!!!
> > 
> > Sure, the http scheme for example.  I can encode into URIs in that 
> > scheme creation dates, directory hierarchies, file types, and all 
> > sorts of things.  It doesn't provide a standard 
> representation for any 
> > one of those, but that's not the point:  it's a schema that "can be 
> > used" to carry such information.  Indeed, the subject of 
> the finding 
> > is when it should be used in that way, and when consumers of URIs 
> > should depend on it having been used that way.
> 
> Ok... I understand the point, but I still think that citing 
> http as such a scheme (as you do in your response above - not 
> the document) sort of over states things. In asking for 
> examples, I was looking for examples where explicit provision 
> was made for carrying additional information, with the 
> explicit intent that the information be recoverable my 
> inspection of the URI. Maybe I read to much into the "CAN", 
> but that is what I read it as suggesting.
> 
> I guess that we can agree to differ on this one.
> </quote>
> 
> I think that the text remains ambiguous between "can" in the 
> sense of 1) a permission to use characteristics of a resource 
> in assigning it a URI; and 2) a reliable channel for metadata 
> between provider and user of a resource.
> 
> I read Noah's response to me as illustrative of 1). I think 
> that many people will read 2). 
> 
> That said, the finding does admit to the notion of documented 
> URI assignment policies (whether implicit in forms or some 
> explicit document eg. [2] which has been superseded though 
> it's successors seem to me not to state such a clear 
> policy.). Without such a stated policy, people are just 
> guessing (maybe correctly) at the significance of substrings 
> within a URI. Even with a stated policy there may be varing 
> levels of commitment to the stability of the policy over time 
> (even if there is a commitment to the persistence of URI that 
> have already been assigned).
> 
> > Marty.Schleiff@boeing.com; CISSP
> > Associate Technical Fellow
> > Cyber Identity Specialist
> > Computing Security Infrastructure
> > (206) 679-5933
> 
> Stuart
> --
> [1] http://lists.w3.org/Archives/Public/www-tag/2006Sep/0095
> [2] http://www.w3.org/2003/05/27-pubrules.html#rules
> 
> 
Received on Friday, 10 November 2006 15:32:22 GMT

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