Re: DTD vs Schema

John Cowan (cowan@locke.ccil.org)
Thu, 10 Sep 1998 13:21:47 -0400


Peter Murray-Rust wrote:

> This is certainly my understanding - in the virtual group we have been very
> careful to restrict ourselves to current DTD functionality.

Except for adding full namespace support. However, we have removed
entities, which are in DCD. As my other posting says, DCD is
required to be a superset of DTD, whereas XSchema is not.

> >- DCD defines an alternative to DTDs
>
> Yes. Exciting new territory. In my mind XSchema may be a transition towards
> this.

It does add new information, but not all that much: namespace
support, datatypes, value ranges. In addition, DCD is silent about
notations.

There is a large common semantic core between DCD and XSchema.
The efforts ought to be merged, providing something that is
compliant RDF, supports the common element/attribute core,
the value ranges, at least some of the datatypes, unparsed
entities, and notations.

...et iterum censeo Carthago delenda est...

-- 
John Cowan	http://www.ccil.org/~cowan		cowan@ccil.org
	You tollerday donsk?  N.  You tolkatiff scowegian?  Nn.
	You spigotty anglease?  Nnn.  You phonio saxo?  Nnnn.
		Clear all so!  'Tis a Jute.... (Finnegans Wake 16.5)