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introducing URIs [was: 13 Aug Arch Doc...]

From: Dan Connolly <connolly@w3.org>
Date: 13 Aug 2002 16:54:30 -0500
To: "Ian B. Jacobs" <ij@w3.org>
Cc: www-tag@w3.org
Message-Id: <1029275670.17704.84.camel@dirk>

On Tue, 2002-08-13 at 15:29, Ian B. Jacobs wrote:
[...]
> [1] http://www.w3.org/2001/tag/2002/0813-archdoc

"1.1 Use of terms URI and URI reference in this document

RFC 2396 divides the world ..."

Hmm... that starts from a perspective that we intend to
obsolete. How about starting from the other perspective:

=======

Chapter 1: Identifiers and resources

The Web is a universe of resources; resources are a generalization
over documents, files, menu items, machines, and services, as
well as people, organizations, concepts, etc. Web architecture
starts with a uniform syntax of identifiers for resources, so
that we can refer to them, access them, describe them, share
them, etc. The syntax employs an extensible set of schemes. Several of
the schemes incorporate established identification mechanisms
into this syntax:

	mailto:nobody@example.org
		mailbox names (including DNS domain names)
	ftp://example.org/aDirectory/aFile
		ftp file names (including DNS domain names)
	news:comp.infosystems.www
		newsgroup names
	tel:+1-816-555-1212
		telephone numbers
	urn:uuid:@@look-up-syntax
		UUIDs, from Apollo/DCE/COM

and others incorporate new naming schemes, including those
introduced as a consequence of new protocols:

	http://www.example.org/something?with=arg1;and=arg2
		HTTP resources
	ldap:@@look-up-ldap-syntax
		LDAP entries
	urn:oasis:SAML:1.0 (@@double-check)
		a namespace from an Oasis specification

Indentifiers in any of these schemes can be composed with
a fragment identifier to yield an identifier for a
resource that is a part of, or view on, another resource:

	ftp://example.org/aDirectory/aDocument#section1
	http://www.example.org/aList#item1
	http://www.example.org/states#texas

Note that while this composition is syntactically fully general,
many cases such as mailto:nobody@example.org#abc
don't make much sense to any deployed software or
specifications.

To summarize, a <dfn>Uniform Resource Identifier</dfn>, or
<dfn>URI</dfn>, is a
character sequence starting with a scheme name, followed by
a number of scheme-specific fields, optionally
followed by a fragment identifier.

This URI syntax is accompanied by a shorthand
<dfn>URI reference</dfn> syntax.
A URI reference is an abbreviation of a URI that can be expanded
by combining it with a base URI. For example, in a document
whose base URI is http://example/dir1/dir2/file1 ,
the URI reference ../file2 abbreviates http://example/dir1/file2
and the URI reference #abc
abbreviates http://example/dir1/dir2/file1#abc.

[[NOTE: The current URI specification, RFC2396, uses a more
constrained definition of the term URI; by that definition,
identifiers that include fragment identifiers are not URIs.
The TAG intends to request a revision to RFC 2396 to adopt
the less constrained definition used here.]]

=======

then continue with 1.2 Resources and URIs.


> [2] http://www.w3.org/2001/tag/#tag-attn
> -- 
> Ian Jacobs (ij@w3.org)   http://www.w3.org/People/Jacobs
> Tel:                     +1 718 260-9447
-- 
Dan Connolly, W3C http://www.w3.org/People/Connolly/
Received on Tuesday, 13 August 2002 17:53:44 GMT

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