DOCBOOK-APPS: One or multiple catalogs for xsltproc? (Was: XML catalogdocumentation)

[Steinar Bang <sb at dod dot no>]

>>>>> Bob Stayton <bobs@caldera.com>:

> I've rewritten my chapter on using XML catalogs with
> DocBook XSL so that it is more complete and accurate.  It
> is available at

> http://www.sagehill.net/xml/docbookxsl/Catalogs.html

There's a mistmatch between the above document, and the libxml2 home
pages.

The above doucment states:
 "Although the name XML_CATALOG_FILES implies multiple names, in fact
  only the first is currently used by xsltproc."
	<URL:http://www.sagehill.net/xml/docbookxsl/Catalogs.html#d0e1941 >

The libxml2 home pages states:
 "The user can change the default catalog behaviour by redirecting
  queries to its own set of catalogs, this can be done by setting the
  XML_CATALOG_FILES environment variable to a list of catalogs, an
  empty one should deactivate loading the default /etc/xml/catalog
  default catalog"
	<URL:http://xmlsoft.org/catalog.html#reference >

Which one is right?  Can there be multiple catalog files?  Or Can
There be Only One?

I hope there can be multiple catalogs.