- From: Williams, Stuart \(HP Labs, Bristol\) <skw@hp.com>
- Date: Fri, 10 Nov 2006 10:09:23 -0000
- To: "Schleiff, Marty" <marty.schleiff@boeing.com>, "Renato Iannella" <renato@nicta.com.au>, <noah_mendelsohn@us.ibm.com>, "John Cowan" <cowan@ccil.org>
- Cc: <www-tag@w3.org>
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 [2] which has been superseded though it's successors seem to me not to state such a clear policy.).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 10:09:38 UTC