At 19:24 1999 07 12 +0900, MURATA Makoto wrote:
2) Announcement of a new draft of XPointer (http://www.w3.org/TR/WD-xptr)
XPointer defines the meaning of the "selector" or "fragment identifier"
portion of URIs that locate resources of MIME media types "text/xml"
and "application/xml".
I have a question. Why do we have to use media types here? If an XML
document contains a link which takes advantage of XPointer, we just know
that the URI references to an XML document and thus do not have to be
notified by XML media types.
I'm not nearly an expert in this area as you are, so I'm a bit
nervous answering, but I'm the one that has been championing that
language in XPointer (and XLink) based on an understanding of things
that is different from what you say above.
My understanding is that the interpretation of the fragment identifier
in URI-references (RFC 2396) is determined by the media type of the
resource referenced by the URI in the URI-reference. It is *not* the
case that any fragment identifer in any URI-reference *embedded in* an
XML resource is necessarily an XPointer. Also, it is not always the
case that one can look at a URI-reference and tell that the fragment
identifier "takes advantage of XPointer." Finally, though the fragment
identifier of a URI-reference into an XML resource must be an XPointer,
there is nothing that prevents XPointer from being used as the syntax
for a fragment identifier into a non-XML resource (i.e., the converse
of "if the resource is XML, the fragment identifier is an XPointer"
is not necessarily true).
So I'd say that is why XPointer must and should mention media types, and
I'd disagree with your statement "If an XML document contains a link which
takes advantage of XPointer, we just know that the URI references an XML
document...."
I hope I will be corrected if I'm mistaken.
paul