RE: [xml-dev] RE: Compelling use case for XML Catalogs?

["Costello, Roger L." <costello@mitre.org>]

John Cowan responded to my post:

> Does XML Catalog have the ability to express this:
>>
>>[snip various conditional things]
>>
>> No, of course not.  Catalogs can only express one thing: when you
>> see this URI, use this other URI instead.  (And ditto for public
>> identifiers.)

The inability of XML Catalog to check for the presence of correct URLs seems like a significant limitation.

XML Catalog only works if: 

    - you have pre-knowledge of exactly what URLs will
      be present in the XML (XSLT, XSD, RNG, SVG, etc.) 
      documents that you receive/process

     - the XML documents will always contain the correct 
       URL; there will never be any accidental or malicious
       alteration of URLs

Yes?

/Roger