Re: Persistent Documents and Locations

Terry Allen (terry@ora.com)
Mon, 21 Aug 1995 16:40:10 -0700


From: "Terry Allen" <terry@ora.com>
Message-Id: <9508211640.ZM20365@dmg.west.ora.com>
Date: Mon, 21 Aug 1995 16:40:10 -0700
In-Reply-To: "Karen R. Sollins" <sollins@lcs.mit.edu>
To: "Karen R. Sollins" <sollins@lcs.mit.edu>, lazear@dockside.mitre.org
Subject: Re: Persistent Documents and Locations
Cc: uri@bunyip.com

I agree with Karen, but would go farther:

>If the object is still
around, in 10 yrs, then the URN for it is still "valid". 

The purpose of the URN is to name.  It still fulfills that function
when the named thing is gone.  For example, we have many titles of
lost (and I mean totally lost) ancient literary works.  Those are
still "valid" titles, and indeed are still useful qua titles.
They don't have to be resolvable to have that utility.

--- Forwarded mail from "Karen R. Sollins" <sollins@lcs.mit.edu>

Date: Mon, 21 Aug 1995 19:21:20 -0400
From: "Karen R. Sollins" <sollins@lcs.mit.edu>
To: lazear@dockside.mitre.org
Cc: uri@bunyip.com, lazear@dockside.mitre.org
In-Reply-To: <9508211941.AA21609@dockside.mitre.org> (lazear@dockside.mitre.org)
Subject: Re: Persistent Documents and Locations
Sender: owner-uri@bunyip.com
Precedence: bulk

   From: lazear@dockside.mitre.org
   Cc: uri@bunyip.com, lazear@dockside.mitre.org
   Date: Mon, 21 Aug 95 15:41:41 -0400

...

   One problem:  who validates URNs, since they are the 
   longest-lived element in the UR* universe?  Like DNS,
   one can find out that a URN is no longer valid.  The issue
   then is to find out a source from which one can get the new
   form of the URN or an alternate URN or confirmation that the
   URN doesn't exist at all anymore.  This is usually an offline
   task (like calling a friend to learn what the real domain
   name is).

	   Walt

Well, no, I think you've misunderstood RFC 1737.  The intention for
URNs is that they are valid in perpetuity.  If the object is still
around, in 10 yrs, then the URN for it is still "valid".  I can't go
into a long diatribe now, but there is a great deal behind the choice
of making URNs global and long-lived.  But, suffice it to say that
URNs don't expire or become invalid.   The resources they name may be
deleted, but the URN should never be re-used or reassigned.  For each
URN the assigment of it happens no more than once, ever.

			Karen


--- End of forwarded mail from "Karen R. Sollins" <sollins@lcs.mit.edu>


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Terry Allen  (terry@ora.com)   O'Reilly & Associates, Inc.
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