SignedInfo Type Attribute

I have a question regarding the SignedInfo "Type" attribute:

In the latest draft version (19991217) section 2.3 asserts the
following:

"The optional Type attribute provides information about the content of
the
 resource identified by URI/IDREF. In particular, it can indicate that
it 
 contains a SignatureProperties, Manifest, or Package element."

If the ressource is identified by an IDREF, I think there is no problem.

But what happens if the ressource is part of an XML document and is 
identified by means of an URI and a XPath Transform? Is this possible
at all? If yes, what does the assignment of the "Type" attribute mean
in that case?

Example:

...
<Signature>
...
      <Reference URI="" Type="&dsig;/Manifest">
        <Transforms> 
          <Transform
Algorithm="http://www.w3.org/TR/1999/REC-xpath-19991116"> 
             AnyXPathTransformSelectingAManifestElement
          </Transform> 
        </Transforms>
...
</Signature>
...  

Regards, Gregor

-- 
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Gregor Karlinger
mailto://gregor.karlinger@iaik.at
Institute for Applied Information Processing and Communications
Austria
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