entity-resolution message

Subject: Re: URI, SOI (off topic)
From: Paul Grosso <pgrosso@arbortext.com>
To: entity-resolution@lists.oasis-open.org
Date: Wed, 22 Nov 2000 09:50:09 -0600
At 16:37 2000 11 21 -0800, Terry Allen wrote:
>| | You can always make a URL or URN for "the latest version
>| | of foo", though I don't know that it would be real useful for
>| | XML.
>| 
>| I use it all the time. The URI
>| http://nwalsh.com/xsl/docbook/html/docbook.xsl always points to the
>| most recent version of the DocBook stylesheets.  
>
>But you wouldn't want to do that with DTDs

Maybe I'm misunderstanding the details here, but something like
this is one of *the* most common uses of a catalog for me.

Specifically, I have lots of documents with a doctype decl of:

  <!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.1.1//EN" 
	"http://www.oasis-open.org/docbook/xml/4.1.1/docbookx.dtd">

or

  <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
	"http://www.w3.org/TR/xhtml1/DTD/transitional.dtd">

and then along comes the next upward-compatible version of the
doctype.  I install the latest doctype and usually toss the older
version (because maintenance of two versions is costly and unnecessary).
Newly created documents will use the new doctype decl, but the existing
documents remain unchanged--and I want both to use the new doctype (dtd).

My existing catalog would look something like (whether the right hand
sides point via HTTP to the official DTD copies or to a local cache is
irrelevant for the purposes of this discussion):

  PUBLIC "-//OASIS//DTD DocBook XML V4.1.1//EN" 
		"doctypes/docbook411/docbookx.dtd"
  PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" 
		"doctypes/xhtml10.dtd"

After installing the new doctype and tossing the old one, I change
my catalog to look something like:

  PUBLIC "-//OASIS//DTD DocBook XML V4.1.1//EN" 
		"doctypes/docbook412/docbookx.dtd"
  PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" 
		"doctypes/xhtml-11.dtd"

  PUBLIC "-//OASIS//DTD DocBook XML V4.1.2//EN" 
		"doctypes/docbook412/docbookx.dtd"
  PUBLIC "-//W3C//DTD XHTML 1.1 Transitional//EN" 
		"doctypes/xhtml-11.dtd"

and I'm all set.  Both old and new documents--regardless of the
doctype decl--use the latest doctype.  We do this constantly with 
doctypes--both our own and public ones (e.g., HTML, XHTML, DocBook) 
in the Arbortext standard distribution.

paul