Schema/DTD represented in sig?

In a similar vein to the question Joseph asked regarding the XML
declaration in a document...

While re-reading the XML XLink Requirements
http://www.w3.org/TR/1999/NOTE-xlink-req-19990224
I was struck by the statement B.2:

 "It must be possible to apply XML link semantics to existing documents
  by modifying the documents' DTDs only, requiring no modification to the
  document instances themselves. 

    For example by supplying appropriate information in an element's
    definition (in the DTD), such as a default ROLE attribute.  This
    provides for layering of XML link semantics onto large bodies of
    XML documents without requiring modification of those documents."

The specific point at issue here is whether changes to a document's
"defining document"; i.e. today its XML DTD, tomorrow its XML Schema,
can alter the interpretation of a document.  If changes can alter
the intended application interpretation, then the signature process
must explicitly account for this in some manner.

One could certainly include this case in the generalization to any
object that is external to the signed document but I suspect that
the DTD or XML Schema is sufficiently important to warrant explicit
treatment in the signature specification.

Received on Wednesday, 23 June 1999 16:38:34 UTC