Re: Globalizing URIs

Martin J Duerst (
Thu, 17 Aug 1995 11:52:26 +0200 (MET DST)

Message-Id: <>
Subject: Re: Globalizing URIs
Date: Thu, 17 Aug 1995 11:52:26 +0200 (MET DST)
From: Martin J Duerst <>

>> Phew, I've been wanting to say that since I read "URN's considered 
>> harmful".  

Is that an existing document? If yes, where could I find it?

>> All this said, there *is* a role for universal names, and that is for 
>> common objects: IETF documents, government documents, Aesop fables, VRML 
>> teapots, etc.  Let's focus on that, rather than having a goal of "keeping 
>> links from breaking".
>Yes, this is a good statement.  I'd say there are two goals:
>a) allow people to make persistent references to documents when this
>   is appropriate
>b) for documents that aren't expected to be persistent, don't convey
>   a false impression that they are.
>That is, a user ought to be able to know whether a link is likely to
>break before he puts it in his hotlist.

Persistence is not just a yes/no decision. If I find a link to a document
about some new software that I might be interested in, I will put it on
my hotlist even if I don't know whether this software will still exist in
two or three years, and even if (assume we have such a distinction) the
link explicitly conveys that it is not strictly persistent.

Even the most persistent document/resource can for some reason suddenly
become obsolete. On the other hand, documents not initially thought
to be persistent can live on and on and on.

Currently, I think most of the documents on the web are semi-persistent
in that they are expected to be there for some years, and in most
cases also will be there for several years. The lower in a hierarchy
of course, the smaller the lifetime, which is more or less natural.
Given the short time the web is working on a wide scale, the average
lifetime of a document (even more so if weighted by access frequency)
may be surprisingly low indeed.

Most of the "missing link" problems are due to a) the things really becomming
obsolete and b) the initial errors and slopyness of server administrators
and document writers that take their time to realize that they better
had to think twice before deciding on/changing a domain name or the
location and name of a doument. At the current rate of growth of the web,
the percentage of such cases will stay the same for a while, but there
is a chance that it gets smaller. As with every technology, it takes some
time for people to find out how it really can and should be used.

Regards,	Martin.