Subject: [urn] 2141bis: Personal observations

From: John C Klensin <[email-masked]>
Date: Sat, 07 May 2016 15:12:20 -0400

Hi.

I've got a number of high-priority things going on in my life
right now. I really don't have time for URNs and probably won't
have time for at least a couple of months.  I'd like to get this
finished and so will try to continue to follow up comments about
things I've said earlier and, when it seems clear what should be
done, work on the documents.  However, the situation, other
priorities, and time pressures are making me a good deal less
tolerant of suggestions that seem to me to reopen old issues or
to change the scope of our work than I normally try to be.

Consequently, if I snap at anyone or seem to respond rudely, I
apologize in advance.  I'm trying to simply not respond to
things that would bring out those reactions (including
especially topics on which I believe the co-chairs need to make
a determination about closed issues), but that may result in
unexpected silences.  I apologize for those, but please do not
take the silence for agreement with whatever has been said.

If any of that makes it inappropriate for me to continue as
editor, tell it to the co-chairs, noting that I've already
suggested to them that I quit.

I hope I can comment on a historical issue without starting an
ultimately-pointless discussion.  It has been clear to several
clusters of people in the WG that the relationship between URNs
and 3986 is not a smooth fit.  For some, parts of that are proof
that URNs are irrelevant or worse.  For a subset of them, that
is an indication that we should have scheme-per-namespace, i.e.,
that urn:example:... should be abandoned and instead mapped into
example:...  For others, 3986 imposes semantic and/or syntactic
rules and limits that are incompatible with 2141 or URN concepts
generally.  Others abhor the distinction between "uniform
resource names" and the urn scheme and whatever it may be taken
as implying.  And still others find 3986 very hard to read
(especially in a URN context), the structure of that document
(at least absent an external oral tradition) far too narrative
and exploratory of options for a normative specification, the
violations of ABNF and related norms with the "one of these must
match, use it" language and the like, just too much to take in
an IETF spec, much less a full standard.  Those groups are
obviously not disjoint although they are almost certainly
separate from those who believe that 3986 is self-contained,
comprehensive, precise, and clear.  

The differences among those various opinions and a desire to
move forward with URNs are the reason we first tried to
disconnect URNs from 3986 URIs entirely and then fell back to a
"syntax only" model.   However, those same differences -- and
the rough edges around the "syntax only" model and 3986
terminology -- can also be used to "prove" that URNs involve
impossible contradictions with URIs and are therefore themselves
impossible (or just a terrible idea) and a dead end.    Those
issues even apply to 2141-style URNs although the new extensions
make URNs a bigger target.

Even if the intent is constructive, reopening issues about the
URN-URI boundary, or even finding new variations on them, can
have only one likely effect, which is killing off the effort to
create a URN standard in the IETF that meets the needs of
various communities who are convinced that they need a URN-style
persistent identifier.  I just hope everyone shares an
understanding about where that leads: it will not stop
communities who believe they need a persistent identifier model
with a syntax that is generally based on the URI model from
creating and using those identifiers.  It won't even prevent
them from labeling such identifiers with the "urn:" scheme name.
They will just do what they thing necessary on a per-namespace
basis, with low likelihood of consistency between namespaces and
even less likelihood of close conformance to the niceties of the
2986 URI definition.   

Whether those URNs will interoperate with the web (or with other
URIs) will depend on how much they deviate from the established
reading of 3986, how established that reading really is, and how
conservative things that have to interpret URIs are about what
they expect.  In some cases, the relevant communities may not
even care.   In others, they may be in a position to take
advantage of an Internet that is increasingly politicized and
economically sensitive in various areas to persuade implementers
and vendors to interpret things their way -- such things have
certainly happened before.

I happen to prefer a single URN framework and standard, even if
it is not as precise about every detail of implementation or
conformance, or as fully-developed in some areas, as many of us
(including myself) would prefer, to a situation in which
everyone does their own thing with whatever guidance and
interpretations they think appropriate.   YMMD, but I hope we
can at least agree that those are possible alternatives.

best,
    john