W3C home > Mailing lists > Public > www-tag@w3.org > February 2005

Re: Significant W3C Confusion over Namespace Meaning and Policy

From: Elliotte Harold <elharo@metalab.unc.edu>
Date: Thu, 10 Feb 2005 13:50:08 -0500
Message-ID: <420BACE0.9030209@metalab.unc.edu>
To: John Boyer <JBoyer@PureEdge.com>
CC: "Roy T. Fielding" <fielding@gbiv.com>, www-tag@w3.org, Bjoern Hoehrmann <derhoermi@gmx.net>

John Boyer wrote:


> That markup can be impacted by changes outside of the content
> if you allow changes the meaning of any name in the namespace or
> if you allow changes to the namespace.

You are positing way more meaning in a namespace and in a name and in a 
signature than has ever been justified by the specs. The namespace says 
nothing about the meaning of a name. A signature says nothing either.

> You said "the signature wouldn't work".   No!  The signature will
> in fact continue to validate, but the subsequent processing of the 
> signed information may not be in accord with what the signer authorized.

The signer did not authorize anything. Any authorization through the 
mechanism of XML signatures is well beyond the scope of the XML digital 
signatures spec.

> So, to fix this error, one has to conclude that neither
> changing the namespace nor changing the semantics of the 
> namespace are permitted.  Again, THIS HAS NOTHING TO DO
> WITH C14N!!!!!

There are no semantics in a namespace. Changing the semantics of a 
namespace is like changing the hair color of the current king of France.

> What I would like instead is for someone to explain to me
> exactly why it is so hard for implementations to be what
> I perceive to be only slightly more intelligent about their
> handling of namespaces.  You make a big deal out of the idea
> of changing the namespace when the language schema changes,
> but this is a trivial thing for an implementer to account for.
> 

It's not merely the issue of changing any one implementation. It's the 
difficulty of changing dozens, hundreds, or even thousands of 
implementations in varying states of maintenance that are deployed on 
millions of systems around the world. Just consider how hard ti's been 
to upgrade browsers over the last ten years, and how long it takes for 
sites to be able to rely on later additions made to HTML. Changing the 
namespace with each minor upgrade would mean browser vendors would 
ignore namespaces in self-defense.

-- 
Elliotte Rusty Harold  elharo@metalab.unc.edu
XML in a Nutshell 3rd Edition Just Published!
http://www.cafeconleche.org/books/xian3/
http://www.amazon.com/exec/obidos/ISBN=0596007647/cafeaulaitA/ref=nosim
Received on Thursday, 10 February 2005 18:50:11 GMT

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