Re: Comments on url-syntax-draft...

Ryan Moats (
Fri, 27 Dec 1996 10:39:46 -0600

Message-Id: <>
Date: Fri, 27 Dec 1996 10:39:46 -0600
From: Ryan Moats <>
To: Larry Masinter <>
Subject: Re: Comments on url-syntax-draft...

Larry Masinter wrote:
> Ryan,
> I don't think we intend for 'a:b:c:d' to be parsed as belonging to
> scheme 'a:b:c', so I think we should fix the regular expression in
> appendix B to treat 'urn:isbn:1-32456-78902-X' as belonging to
> scheme 'urn' and not scheme 'urn:isbn'.
> I don't know how to proceed on the issue of changing the URL draft to
> describe URNs and URN parsing. I think if we're going to proceed from
> Proposed Standard to Draft Standard that we are not supposed to add
> functionality, and that the only changes we can make are those that
> are consistent with current practice.

In my mind you have two options:  (1) Delete the text in Section 1.1
relating to URNs and URIs or (2) Change the Appendixes and elsewhere
to fix the problem above.  

I forsee problems in the URL draft with any potential "meta-scheme",
an example of which is providing checksums for a URx if it maintains
its current section 1.1 language.

The point is that the current draft is unacceptable in its making a
statement about URNs without realizing that URNs are a superset of URLs
and should not be bound by the URL syntax (in fact one could argue the

> I don't know why URNs don't require any determinist structure to URNs
> while it seemed important that URLs require such a structure for URLs.

One reason is that URNs are more general than URLs.  Another is that
URN syntax pushes the deterministic structure off to the namespace
resolver.  Another is that URLs are inherently tied to the underlying
filesystem structure.  There are more, but this should be a start.

> (Actually, URLs don't make such a requirement, they just don't
> guarantee that relative URLs work if you don't use it.)

??? I don't see this.  I see that absolute URLs have a definite
structured syntax throughout the draft.