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Re: New draft TAG Finding on The Self-Describing Web

From: Paul Prescod <paul@prescod.net>
Date: Wed, 30 May 2007 11:02:58 -0700
Message-ID: <1cb725390705301102i7b643fcaia8c7b4360c65122f@mail.gmail.com>
To: "noah_mendelsohn@us.ibm.com" <noah_mendelsohn@us.ibm.com>
Cc: www-tag@w3.org

I'm glad to see progress on this draft. I'd like to address one point.

"The namespace name URI serves at least two roles: the most obvious
and the most widely understood is that it serves to distinguish
expanded names in one namespace from those in another; the other role,
and the one that's most important for purposes of this finding, is
that it provides Web identification for the namespace itself."

Is there not a third role, arguably more important, of providing
human-readable documentation for the namespace? Messaging systems and
documents outlive the creators of them, and just like computer code,
they need architecture documents that describe them. Unlike computer
code, the documentation is seldom embedded into the message/document.

In Java or any other language, I might write a comment like this:

if(element.tagName=="Foobar"){  // See
http://standards.body.org/standard/documentation

}

But in XML, I would just write this:

<Foobar xmlns="http://standards.body.org/standard">

</Foobar>

The primary virtue of this is that as a document AUTHOR I do not need
to know the URI for the documentation of the vocabulary I'm using.
Knowing the URI for the namespace serves both purposes.

In years of discussion about the value of namespaces I have found that
people are often (rightly!) skeptical that anything of value to the
machine will be referred to by a namespace but they will readily admit
that it is valuable to point to something of value to a human being.

The following existing namespace URIs are much more useful to humans
than they are to machines:

 * http://www.w3.org/2001/XMLSchema
 * http://www.w3.org/1999/XSL/Transform
 * http://www.w3.org/TR/REC-xml-names/

As always, SOAP is an exception
(http://www.w3.org/2001/12/soap-envelope). It provides a schema, but
there are comments in the schema pointing to the REC.

I believe that vocabulary-creators have a responsibility to those who
come later to put up human-readable documentation.

 Paul Prescod
Received on Wednesday, 30 May 2007 18:03:07 GMT

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