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Re: Significant W3C Confusion over Namespace Meaning and Policy

From: Patrick Stickler <patrick.stickler@nokia.com>
Date: Fri, 18 Feb 2005 10:32:55 +0200
Message-Id: <a78338226f731bacb330ffb414d237e9@nokia.com>
Cc: Norman Walsh <Norman.Walsh@sun.com>, www-tag@w3.org
To: "ext Harry Halpin" <hhalpin@ibiblio.org>

On Feb 17, 2005, at 18:11, ext Harry Halpin wrote:

> However, it does seem like a namespace document would be a sensible 
> place to put such a schema, although - of course - it's not required. 
> One could put the schema anywhere - however,  then the question is how 
> to find it.
> DocBook documents could be defined by their schema, and one could
> find the schema in the namespace document 
> (http://www.oasis-open.org/docbook/...) or somewhere else entirely, 
> like your hard drive. I think the reason people are talking at 
> cross-hairs is
> that they think the pro-"namespace document" camp are saying that it 
> would be useful to upgrade RDDL or something like it to help with 
> versioning issues, and the anti-"namespace document" camp thinks that 
> we want to make having a namespace document a necessary condition of 
> the namespace URI - which as the spec says and use shows, is obviously 
> not true. However, as a *optional* place to put things like versioning 
> info, a namespace document seems just as good as a URI.

We need a consistent, standardized, and (potentially) globally
ubiquitous solution which provides effective discovery of
information about the models needed to properly interpret
data instances.

Namespace documents fail to provide such a solution.

Adding versioning support (however that might be done) will not
enable namespace documents to be less ambiguous or more


> 				-harry
> On Thu, 17 Feb 2005, Norman Walsh wrote:
>> / Harry Halpin <hhalpin@ibiblio.org> was heard to say:
>> | While I agree that Henry is technically correct (technically as in
>> | "read the specification"), this giant perma-thread clearly shows
>> | that there are simply problems in keeping track of versioning with
>> | namespaces. If a namespace can have an infinity of names, then
>> | perhaps this should be repaired in a new spec, since having an
>> | infinity of names makes versioning difficult. Either one has a
>> | separate URI for each version, or a representation is returned by
>> | the URI that contains the versioning information.
>> In the general case, I simply do not believe that there is any
>> relationship between the namespace name and the set of terms in the
>> namespace.
>> Consider the case of DocBook. DocBook V5.0 will be in a namespace. I
>> do not expect that namespace to change. Ever. It will be the namespace
>> for V5.0, V5.1, V6.0, ... V17.3, etc. ad nauseum, of DocBook.
>> If the document you have in hand validates against the DocBook V5.3
>> schema, it is a DocBook V5.3 document. If it validates (instead of, or
>> also) against the V5.0 schema, it is a DocBook V5.0 document. Turning
>> that around, as a consequence of the versioning policy of the DocBook
>> Technical Committee, I can predict that every V5.0 document will also
>> be V5.3 document.
>> This is not the only possible namespace/versioning strategy, but for a
>> bunch of practical reasons, it is the best policy for DocBook and I'd
>> resist any attempt to define a general policy for namespace/versioning
>> that prevented the DocBook policy.
>>                                        Be seeing you,
>>                                          norm
> -- 
> 				--harry
> 	Harry Halpin
> 	Informatics, University of Edinburgh
>         http://www.ibiblio.org/hhalpin
Received on Friday, 18 February 2005 08:33:47 UTC

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