Namespace URI address resources

Paul Prescod paul at
Wed Jun 16 12:57:43 BST 1999

Andrew Layman wrote:
> I suggest that there is a vast difference between something such as a
> schema, which creates identifiers and gives them a definition, and other
> resources such as style sheets that may be permanently or ephemerally
> associated with those identifiers.  One defines the data; the other
> indicates processing.

It seems to me to be entirely debatable whether a schema defines element
and attribute types or whether it just constrains their use. My personal
take is that the schema merely contrains use.

Consider that I have a document that is an HTML document. Is the most
important feature of the P elements in the document that they are globally
known as "HTML paragraphs" (their semantics) or the details of the element
type declaration in the DTD? If I swap in another variant of the HTML DTD
with another set of element type declarations have I completely changed
the nature of those element types?

If I have a CDF document without a DTD or schema would it be accurate to
say that those element types are "undefined"? Or merely not defined in a
manner that would allow a computer to check validity using a standardized
schema language?

If I have two schemas for a document, in two different schema languages,
must one be the "definitive" schema and the other non-definitive?

 Paul Prescod  - ISOGEN Consulting Engineer speaking for only himself

[Woody Allen on Hollywood in "Annie Hall"]
Annie: "It's so clean down here."
Woody: "That's because they don't throw their garbage away. They make 
        it into television shows."

xml-dev: A list for W3C XML Developers. To post, mailto:xml-dev at
Archived as: and on CD-ROM/ISBN 981-02-3594-1
To (un)subscribe, mailto:majordomo at the following message;
(un)subscribe xml-dev
To subscribe to the digests, mailto:majordomo at the following message;
subscribe xml-dev-digest
List coordinator, Henry Rzepa (mailto:rzepa at

More information about the Xml-dev mailing list