To: uri@bunyip.com
In-Reply-To: peterd@bunyip.com's message of Fri, 25 Feb 1994 10:16:11 -0800 <94Feb25.101631pst.2795@golden.parc.xerox.com>
Subject: Re: URN to URC scenario
From: Larry Masinter <masinter@parc.xerox.com>
Message-Id: <94Feb25.114233pst.2732@golden.parc.xerox.com>
Date: Fri, 25 Feb 1994 11:42:20 PST
> If we separate out architecture from implementation,
> there's the question of what these things should be look
> like and the question of how we set up and adminster
> specific naming authorities. If the fact that the current
> naming authority for DNS has practices that we'd like
> changed (such as reissuing a name that is allowed to lapse
> - do they _really_ do that?), then let's look at the cost
> and feasibility of changing these practices. On the other
> hand, that does seem very much an implementation issue and
> thus separate from the discussion of what the URN format
> should look like and what properties it should have and so
> on.
The proposal that urns use DNS is an implementation proposal, and I
was speaking to that. The only architectural concern I have is that
if you use organization NAMES in URNs you run some risk that someone
else later will want the same name.
Here are some examples that I think fit within the proposal and
might be workable:
internet/rfcs/1024 For RFCs, I think this will work.
prentice-hall/books/2014 For a publisher
xerox/parc/reports/p931204 For a tech report from an organization
but I'm not so sure about organization names that are abbreviations
or are likely to be reused:
tic/1024 Is this Texas Internet Consultants? Technical
Information Center?
nu/reports/1010
Northeastern University? Northwestern? North?
A scheme where URNs use organization NUMBERS rather than NAMES might
avoid the problem of registered business names, trademarks, etc. This
is the tack taken for the ISO public identifiers, is used in ISBN
numbers (although in a way that doesn't scale) and it has some other
definite advantages.... you're less likely to get bogus URNs if the
hierarchy is numeric. It would definitely be the case that you
couldn't just `start using' a URN top-level name without registering
it with IANA (in order to get a number assigned) but I think that has
some real appeal.
If we accept a hierarchical syntax xxx/yyy/zzz/name for URNs, I can
still see the following proposals:
a) URNs can be alphabetic at any level (current proposal)
b) (a) with the constraint that no `abbreviations' are allowed
c) the top level of the URN hierarchy is numeric, with numbers
assigned by IANA
d) URNs are numeric except for the leaf level. Each level of the
hierarchy must run its own IANA-equivalent for assigning
numbers to sub-naming authorities.
e) URNs are completely numeric (like ISO public identifiers)
I'm personally leaning toward (d). Other opinions?