Anonymous content types (WAS: Re: XML trade off 1 - DTD vs XML Schema)

John E. Simpson simpson at
Mon Jul 19 22:09:30 BST 1999

At 03:18 AM 7/20/1999 +0800, Rick Jelliffe wrote:
>In a little note "Richer Anonymous Content Types" 
>I have suggested that there are other declared content
>types apart from EMPTY and ANY that might be
>useful for XML Schemas.   (The content typing is anonymous
>in that it specify kinds of content models without
>actually naming the element types. This might fit in
>with XML document usage better than simple
>"open" and "closed" content models.)
>I suggest:

Ah. Thanks for the explanation. 

So (acknowledging that you mean it to apply only to XML schemas, and that
the following examples don't conform to legitimate XML DTD syntax) you're
suggesting element content models such as:


(The king element may contain any other single element)

	<!ELEMENT hands PAIR >

(The hands element may contain any *pair* of other elements)

	<ELEMENT citizens UNIQUE >

(The citizens element may contain any number of child elements, but each
child may appear only once within the citizens element)

Like that? These would all be subtypes of ANY, no?

John E. Simpson          | It's no disgrace t'be poor, 
simpson at      | but it might as well be.
                         |            -- "Kin" Hubbard

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