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URI terminology, esp. in XML specs

From: Dan Connolly <connolly@w3.org>
Date: Mon, 10 Jan 2000 09:34:58 -0600
Message-ID: <3879FC22.7A86AA5F@w3.org>
To: uri@w3.org
I have recently spent a considerable amount of time studying
the URI spec
[1]	http://www.ietf.org/rfc/rfc2396.txt
and I discovered, somewhat to my surprise, that it
defines the terms "URI reference" and "absolute URI" very precisely,
        (a) it doesn't define the term "URI", syntactically (!!!)
        (b) it doesn't give a term for an
absolute-URI-with-optional-fragment-id , i.e. the result of combining
a URI reference with an absolute URI.

This is pretty awkward, since an absolute-URI-with-optional-fragment-id
really what we meant when we wrote "URI reference" in:

"An XML namespace is a collection of names, identified by a URI
-- http://www.w3.org/TR/1999/REC-xml-names-19990114/#sec-intro

We used "URI reference" because "absolute URI" excludes fragment
and we wanted
to be a valid namespace identifier.

isn't a namespace identifier, until you combine it with a base

Another example:

"The locator attribute provides a URI-reference that identifies a remote
resource (or sub-resource)"
-- http://www.w3.org/TR/1999/WD-xlink-19991220/#Local Resources for an
Extended Link

URI-references don't identify remote resources; absoluteURIs do. The
"or sub-resource" makes it clear that the author intends to allow
So again, what's needed is a term for

It was called fragmentaddress in RFC1630.

If formal systems float your boat, you can take a look at my formalism
of this stuff in larch:
        http://www.w3.org/XML/9711theory/URI.html (HTML version with
                nasty hacks for math symbols)
        http://www.w3.org/XML/9711theory/URI.lsl (original ascii LSL

part of
        "Specifying Web Architecture with Larch"

which gives pointers explaining larch etc.

I used the term URIwf for absolute-URI-with-optional-fragment-id, and
I used absoluteURI and URI_reference with their rfc2396 meanings.

Dan Connolly
Received on Monday, 10 January 2000 10:35:29 UTC

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