Re: [xml-dev] My report on experiments with unused namespaces

[Richard Salz <rsalz@us.ibm.com>]

> There are several reasonable starting points for defining what parts of 
> an XML document are information-bearing: two that agree reasonably 
> closely (though not 100%) are the XML canonicalization spec and the XDM 
> data model.

Note that QName's in content meant that another XML c14n method had to be 
defined, one where "unused" namespaces are stripped, unless specifically 
directed to be included.

> one might 
> imagine a stronger form of canonicalization that, for example, moves all 

> namespace declarations to the outermost element, changes the prefixes, 
> and deletes namespace declarations that are not used in any element or 
> attribute names. You might take the view that people should write their 
> applications in such a way that they continue to work after such a 
> change; and others might legitimately take a different view. This is in 
> the realm of "best practice", where no two people will agree.

This would mean that nobody could take a signed document and embed it in 
another one, such as SOAP.  A use case I kinda care about :)

        /r$

--
STSM, WebSphere Appliance Architect
https://www.ibm.com/developerworks/mydeveloperworks/blogs/soma/