Don't put descriptive info in a URI, only identifying info

From: Dan Connolly (connolly@w3.org)
Date: Mon, Dec 21 1998


Message-ID: <367E8444.7115@w3.org>
Date: Mon, 21 Dec 1998 11:24:20 -0600
From: Dan Connolly <connolly@w3.org>
To: ietf-url@imc.org, www-tv@w3.org
Subject: Don't put descriptive info in a URI, only identifying info

In a review of a draft of requirements for a TV URL scheme[1],
I just noticed:
|4.The URI scheme MUST support for OPTIONAL information
|     from which it MUST be possible for a receiver to determine
|     the time period(s) within which the resource can be retrieved
|     from the (also resolved) location. 

This conflicts with a design principle I hold about URIs,
explained in my message to the uri list in Feb 1997[2]:

|If you're talking about "the document XYZ, which has title
|ABC" then then ABC must not be part of the identifier. Because
|you might want a reference ala "the document XYZ, which
|has author Fred" to be recognized as the same resource.
|
|On the other hand, you might refer to a resource using
|a restrictive clause: "the service ZZZ that started in 1996".
|In this case, "the service ZZZ that started in 1995" is a
|distinct resource. So the year is part of the URL.

I started to (a) ask the editors of [1] to
cite the URL scheme guidelines[3], and (b) remove requirement
4 since it conflicts. But [3] doesn't say anything about
[2], so first I'm asking for [3] to reflect [2].

I think [2] provides enough text for the editors to work
with, but if it doesn't, let me know and I'll try to
provide some.


[1] TV Broadcast URI Schemes Requirements 
                       26th November 1998 
Editors: 
     Warner ten Kate <tenkate@natlab.research.philips.com>. 
     Gomar Thomas <gomer@lgerca.com>. 
     Craig Finseth <craig@finseth.com>. 
http://www.w3.org/TV/TVWeb/TVWeb-URI-Requirements-19981126.html

[2] Re: Attributes should only be there if part of the name/address
space
Dan Connolly (connolly@w3.org)
Thu, 20 Feb 1997 10:05:36 -0600 
http://www.acl.lanl.gov/URI/archive/uri-96.messages/0232.html

[3]
Title           : Guidelines for new URL Schemes
Author(s)       : L. Masinter, H. Alvestrand, D. Zigmond, R. Petke
Filename        : draft-ietf-urlreg-guide-04.txt
Pages           : 6
Date            : 16-Nov-98
ftp://ftp.ietf.org/internet-drafts/draft-ietf-urlreg-guide-04.txt

-- 
Dan Connolly
http://www.w3.org/People/Connolly/