Re: URN fodder...

Paul Hoffman (ietf-lists@proper.com)
Tue, 28 Mar 1995 15:02:49 -0700


Message-Id: <v02110103ab9e32f66cb9@[165.227.40.27]>
Date: Tue, 28 Mar 1995 15:02:49 -0700
To: pierre@indirect.com (Pierre Landau)
From: ietf-lists@proper.com (Paul Hoffman)
Subject: Re: URN fodder...
Cc: uri@bunyip.com

>Suppose that someuser@somemachine.someuniversity decides to "publish" a
>document, be it an HTML one or otherwise.  As things exist now, the user
>tells friends about it, or puts a pointer on some HTML page to it.  Ideally,
>the user would register the document, obtain a URN, and distribute the URN;
>other copies of the document would share the URN and therefore the access load.

There is not a one-to-one mapping between URNs and HTML pages in your
example. Many different URNs could point to one URL, and a single URN can
point to many different URLs. In the S/A/E system Ron and I proposed, there
is no forced "registration". The distribution of URNs by word of mouth is
exactly the same as the distribution of URLs you describe. This is true (I
believe) for all the current URN proposals: a URN can include URLs for
whatever the author wants.

>1) Unless some encapsulation is used, how is a document to be tagged with
>its URN? Suppose I copy  a public-domain JPEG image of Jupiter from a server
>which is very slow. I have its original URL, but not necessarily its URN, so
>although by my having copied it I might make it available to others on the
>net, they will not be able to identify it as the same object.

I think there is confusion here. Because there isn't a one-to-one mapping,
there is no "its URN". In the example you give, there many be dozens of
URNs created by different people that all point to the image as it exists
on the slow server. One such URN is someone's view of "all pictures of
Jupiter everywhere on the Internet"; another URN might be "the most
frequently accessed files on ftp.slow.com"; yet another might be "picture
427 of Jupiter at the sites I like". You are also free to publish as many
URNs about your copy (or of the original copy) as you want. You might also
contact the publishers of other URNs that point to the original copy and
ask them to include the URL to your copy in their URNs.

This situation is common in the publishing world. If I've written a book,
how do I find out what's been published about it? How is it cited? How is
it cataloged? There are no restrictions.

>2) URN search ability is vital.  Suppose I'm writing a paper, and want to
>refer to other papers.  I need to be able to find the appropriate URNs for
>those papers, even though I may know only author and title, but perhaps not
>the journal name.

Well, if you really "need" that, you're probably out of luck. On the other
hand, if most URN publsihing sites serve the "urn+a" optional URN we
suggest in the S/A/E proposal, it will be pretty easy to create the URN
equivalent of Web spiders for URNs, and many such catalogs will exist.
Without such a mechanism, catalogs would be essentially impossible except
by collecting URNs in free text; with it, they are fairly easy, as long as
you know the names of sites that resolve URNs.

>3) Using the hierarchical DNS scheme for registering publishers works well
>with departments at universities, but perhaps less well with a publisher like
>joe@orion.tucson.az.us.   Perhaps the Library of Congress or a similar
>entity is a more appropriate "authority" to register publishers with.

Anyone can be such an authority. Assuming that orion.tucson.az.us is a
basic Internet connection provider who is running URN server software and
you are a user, they may have a program where you send them the resolution
results and a requested URN name, and a program simply creates that URN
(assuming the name is unused).

The situation is similar to Internet providers and "Web space for sale":
some say any user can put up a Web page, others charge, others say you
can't do it on their site. Some people switch providers so they can get
free Web space. Many sites exist only for the Web publishing. The
situations with being able to publish URNs may turn out to be similar.

--Paul Hoffman
--Proper Publishing