Re: [apps-discuss] An XML RFC primer?

Tim Bray <> Tue, 11 January 2011 19:44 UTC

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Date: Tue, 11 Jan 2011 11:46:31 -0800
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From: Tim Bray <>
To: "t.petch" <>
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Subject: Re: [apps-discuss] An XML RFC primer?
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On Tue, Jan 11, 2011 at 9:08 AM, t.petch <> wrote:

>  - impossibility of validating documents with XSD (possible with DSDL).

The general lousiness of XSD is now well-known.  Atom was very happy
with RNG, but ymmv.

> Netconf did take advice from the XML Directorate, and they were plain wrong, in
> one key regard, which has turned out to be an issue that has taken years so far,
> and as yet is unresolved (the question they failed to answer correctly was what
> is and is not valid XML? the consequence is an inability to parse XML documents
> transported by Netconf as currently specified).

Huh?  Formally, "valid" means "has a DTD and conforms to it" but
almost nobody uses DTDs any more.  Whether something is or is not XML
is not in any doubt either de jure or de facto, we have good
interoperability among parsers these days.  If Netconf XML can't be
parsed, the specification must have some awful problems.

I've certainly seen some lousy XML-based protocols here and there, but
this the first instance of "inability to parse" I've run across.