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Re: Namespaces 1.0: URI syntax a NSC

From: Henry S. Thompson <ht@inf.ed.ac.uk>
Date: Thu, 22 Oct 2009 12:00:40 +0100
To: Bjoern Hoehrmann <derhoermi@gmx.net>
Cc: xml-names-editor@w3.org
Message-ID: <f5bbpjzzo9z.fsf@hildegard.inf.ed.ac.uk>
Hash: SHA1

Bjoern Hoehrmann writes:

>   In http://www.w3.org/TR/2009/PER-xml-names-20090806/ the level of non-
> conformance when using non-URIs as namespace names is unclear. Section 7
> does not mention this issue, section 3 makes it a MUST-level violation,
> and section 8 implies it is a NSC violation. However, there is no NSC on
> this issue.

Thanks for your comment.  The Working Group discussed this and
reviewed the relevant bits of the spec. in detail.  We concluded that
in fact the situation _is_ clear.

With respect to section 7, wherever RFC 2119 language is used
it creates conformance requirements in a specification, and section 7
says that a conformant document is one which conforms to the spec.  So
in conformant _documents_, it is clear that namespace names are
non-empty URI references.

It did not seem to us that section 8 implies it is an NSC violation --
it says that processors are exempted from reporting non-URI-ref
namespace names, and classifies that as a failure of namespace
well-formedness.  And, as argued above, section 7 includes not just
NSCs, but conforming to _all_ use of RFC2119 language, as part of

We have made a change in section 8, prompted by this review -- instead

  with the exception that it is not REQUIRED to check that namespace
  names are legal URIs.

it will read

  with the exception that it is not REQUIRED to check that namespace
  names are URI references [RFC3986].

to bring it into exact alignment with the wording in section 3.

> This is confusing especially in the context of the XML specification,
> which has MUST-level requirements not covered by well-formedness or
> validity. I am assuming that this is supposed to be a NSC, so adding
> an explicit NSC for it would resolve this problem.

The Working Group does not agree that all RFC 2119 language must be
located in the context of NSCs (or WFCs or VCs, in the XML context) in
order to have normative force.

We do acknowledge that this is a difficult area where opinions differ,
and it might be worth bringing this up in a larger context for W3C
specs as a whole.

Please let us know if you are willing to accept this resolution in the
current instance, pending the outcome of any further higher-level

- -- 
       Henry S. Thompson, School of Informatics, University of Edinburgh
                         Half-time member of W3C Team
      10 Crichton Street, Edinburgh EH8 9AB, SCOTLAND -- (44) 131 650-4440
                Fax: (44) 131 651-1426, e-mail: ht@inf.ed.ac.uk
                       URL: http://www.ltg.ed.ac.uk/~ht/
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Received on Thursday, 22 October 2009 11:01:14 UTC

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