Subject: Re: References

From: John Stanley <[email-masked]>
Date: Fri, 22 Apr 2005 11:31:48 -0700 (PDT)

"Charles Lindsey" <chl@xxxxxxxxxxxxxxxx>:

>Frank Ellermann <nobody@xxxxxxxxxxxxxxxxx> writes:

>>No References => no follow-up.

>Which indeed follows from the fact that USEPRO says that a followup agent
>MUST incorporate a References header (and do it correctly, of course).

Unfortunately, RFC2822 says only SHOULD regarding the References header 
and followups, and USEFOR says that the References header is defined as 
found in RFC2822 (and for the pedants who cannot identify the context of 
this discussion, I'll add "other than a few syntax changes that don't 
change the requirements for usage, which is the context of this discussion 
here.) So References in a followup is only a SHOULD, and if USEPRO says 
otherwise, it contradicts both RFC2822 and USEFOR. While one of those we 
can modify for good reason, the other is the result of our modifications, 
and we did NOT modify the References header to make it mandatory in any 
use.

>A pure logical deduction indeed. But for the removal of all doubt, and to
>emphasise the difference from the treatment of "replies" in RFC 2822, we
>used to say that as well. Now we don't (because our Chair so decrees), but
>because it was redundant nothing has actually changed (John's claims to
>the contrary notwithstanding).

Stop putting words in my mouth, Charles. 

>Is is the the thing which is produced (as carefully defined in USEPRO) by
>a "followup agent", or is it anything that has a References header. I
>prefer the former (and you seem to have been using it in that sense), and
>John has been arguing for the latter. Technically, it makes no difference
>so long as we use the term consistently.

Stop putting words in my mouth, Charles. You don't understand what I've
said, so you are the last person who ought to be pretending you do. You
being the editor and able to make willy-nilly changes to the drafts does
NOT give you the right to put words specifically in MY mouth, even though
you are putting words regularly into the mouths of the group as a whole.

You are apparently incapable of differentiating between "poster intends a 
followup in what he sends" and "reader detects a followup in what he 
gets." The previous standards and drafts have said that the intent for 
something to be a followup by a poster REQUIRES a References header to be 
inserted (MUST), and otherwise that header is prohibited. That means that 
the READER can then determine what the poster intends to be a followup by 
looking for a References header.

And yes, Charles, when you say "non-followups MAY contain a References 
header", you have removed that ability to DETECT at the reader's end of 
the pipe what is and is not intended to be a followup. That is a change, 
despite your repeated denials.

---

From: "Charles Lindsey" <[email-masked]>
Date: Mon, 25 Apr 2005 14:16:34 GMT

>and followups,

Please show me where the word "followup" is to be found in RFC 2822.

If you use your newsreader to send an Email reply to the author of a News
article, then indeed you (only) SHOULD include a References header (and
In-Reply-To as well to do the job properly).

If you use your newsreader to post a News followup to a News article
(usually in the same newsgroups as the precursor) then RFC 2822 is silent
on the issue (because the whole purpose of RFC 2822 is to tell you how to
construct a proper Email.

USEFOR incorparates, by reference, many concepts from RFC 2822, including
many headers and their meanings (semantics). But nowhere does USEFOR
equate the concepts of "Email Reply" with "Netnews Followup". Therefore
they remain different concepts with different rules.

I grant you that the concepts are sufficiently similar that, wherever we
say that News Followups are different in some way from Email Replies (e.g.
MUST rather than SHOULD), then we need to draw attention to this.

Our Chair has ruled that the correct place to say such things is in USEPRO
rather than USEFOR.

>looking for a References header.

If a poster intends a followup, then a References header is REQUIRED.

If the poster does not intend a follouwp, but nevertheless includes a
References header (e.g. in a multi-part FAQ, or to stitch together a
message/partial), then what is the effect?

>despite your repeated denials.

Exactly. That has never been denied. You cannot tell from looking at the
References header whether the poster intended to write a followup, or
merely intended that it should be threaded like a followup (with all the
other benefits accruing from a References header).

So f*****g what? Why should the reader care? So long as the reader (or his
agent) does the Right Thing (as intended by the poster in both cases), why
should anybody get upset?

-- 
Charles H. Lindsey ---------At Home, doing my own thing------------------------
Tel: +44 161 436 6131 Fax: +44 161 436 6133   Web: http://www.cs.man.ac.uk/~chl
Email: [email-masked]      Snail: 5 Clerewood Ave, CHEADLE, SK8 3JU, U.K.
PGP: 2C15F1A9      Fingerprint: 73 6D C2 51 93 A0 01 E7 65 E8 64 7E 14 A4 AB A5

---

From: Ken Murchison <[email-masked]>
Date: Tue, 26 Apr 2005 11:00:47 -0400

> and we did NOT modify the References header to make it mandatory in any 

I think you're taking the fact that neither RFC2822 nor USEFOR mandate 
References too literally.

USEFOR only documents what is necessary to make an article syntactically 
correct, not what makes it useful in the Netnews world.  In this regard, 
References is optional.  A "followup" article which doesn't have a 
References header is still syntactically correct.  This doesn't mean 
that its recommended or useful.

USEPRO documents how to construct an article ("followup" or otherwise) 
which will play nice in the Netnews world.  In this regard, USEPRO can 
and should mandate that References be present in "followup" articles. 
USEPRO (and possibly USEAGE) will dictate when the optional headers 
documented in USEFOR should and should not be used.

I don't see a contradiction here, but maybe I'm wrong.

-- 
Kenneth Murchison     Oceana Matrix Ltd.
Software Engineer     21 Princeton Place
716-662-8973 x26      Orchard Park, NY 14127
--PGP Public Key--    http://www.oceana.com/~ken/ksm.pgp

---

From: Frank Ellermann <[email-masked]>
Date: Wed, 27 Apr 2005 09:11:16 +0200

Ken Murchison wrote:
 
> I don't see a contradiction here

There's no contradiction.  We have followup => references,
and after you've modified the definition as indicated in...

 <[email-masked]>
| Done.

...this issue is settled for Usefor-04 and the future RfC,
as far as I'm concerned.

One WG member apparently wants an equivalences in the form
of followup <=> references and followup <=> 2822-reply, but
that's obviously wrong, and the proposed alternative of no
relation at all between followup and references is also wrong.

                        Bye, Frank

---

From: "Forrest J. Cavalier III" <[email-masked]>
Date: Wed, 27 Apr 2005 07:14:25 -0400

> relation at all between followup and references is also wrong.

Did anyone ever advocate that 2822-reply => followup?

It isn't one WG member that wants this:
followup <=> references

I think it is a requirement that a news client be able to determine
"followup" by inspecting the article headers.

If it is not a requirement, then the term "followup" is meaningless
and should not appear in any document.

In support of this, I point that the References header is for
the use of the READER, not the POSTER.  The poster already knows how
all the articles are related.

Also, if not mandating anything required by the READER for
interoperability, how can a document merit anything stronger than a
"MAY add a References header"?  (And if it is this weak, what's the
point?)

Frank, you allowed that followup => references.  If you don't
hold that references => followup, then does the standard allow an
article to reference more than one thread?  I think that
allowing References to appear in an article which is not a reply
to a single article (which I thought was the term "followup"),
leads to undecidable actions about threading. What is the READER
agent supposed to do in that situation?

Is there a term for articles that can have references but are
not followups?  If not, why the special term "followup"?  What
does the apperance of References header mean, from a READER perspective?

Sure it is POSSIBLE to define a standard which describes unambiguous
construction of an article, but not unambiguous interpretation of that
article.  But I think that's ludicrous.  Is there any other IETF standard
that does this?

---

From: Frank Ellermann <[email-masked]>
Date: Thu, 28 Apr 2005 14:04:33 +0200

Forrest J. Cavalier III wrote:
 
> I think it is a requirement that a news client be able to
> determine "followup" by inspecting the article headers.

Maybe you like to join Bruce and some others including me
in our time travel excursion to fix some RfCs, you could
be the advisor to Dave Crocker when he fixes STD 11 4.6.3.
We could do radical things like publishing s-o-1036 as RfC.

Seriously, this "requirement" is wishful thinking, you find
it as See-Also in s-o-1036.  All we can do today is to say
how a followup is supposed to be created and how References
are trimmed.

We cannot guarantee that all References were built this way.
The very best we can do is to be silent about more creative
ways to generate References.
 
> If it is not a requirement, then the term "followup" is
> meaningless and should not appear in any document.

"Followup" has a perfect meaning defined by Followup-To (or
Newsgroups).

> What is the READER agent supposed to do in that situation?

It's supposed to expect the worst, but to work for the 99.9%
ordinary followups.  In the same way as it did for the last
decade.  

BTW, I've tested the effect of an article referencing itself
on this list some moths ago.  Let's say that I won't test
this again.

> Is there a term for articles that can have references but
> are not followups?

How about "literal Reference" ?  "STD 11 4.6.3 Reference" ?
"Multi-2822 quasi-In-Reply-To" ?  Or good old "See-Also" ?

> why the special term "followup"?

Maybe ask Henry or Bruce, it must be very old, "Followup-To"
is very old.  For me nothing before s-o-1036 is real, all I
knew about Usenet before s-o-1036 was "Emily Postnews", and
the fascinating differences from FidoNet, because I used to
hang out in a gateways NG ("echo" from my POV) for some time.

That's also the reason why I consider attempts to devalue
Usenet Message-IDs to some <id-left@id-right> as blasphemy.

                      Bye, Frank

---

From: "Charles Lindsey" <[email-masked]>
Date: Thu, 28 Apr 2005 11:29:40 GMT

>"followup" by inspecting the article headers.

OK. Then you need to tell us exactly WHY that requirement is needed.

As opposed to a requirement "that a news client be able to determine
articles that the poster intends to be treated the same way as followups
...".

>and should not appear in any document.

The term "followup" has to appear in our standards, if only because we
have to explain the purpose of the Followup-To header. And we have to
explain the duties of a followup agent. And USEAGE (which is not
standards-track) also explains how to contruct attributions and quotations
in followups.

>all the articles are related.

Indeed, but the POSTER gets some say in how the READER gets to view his
articles by including (or not including) a References header.

>agent supposed to do in that situation?

Both USEPRO and RFC 2822 state explicitly that they make no provision for
followups/replies to multiple precursors, though they do not explicitly
forbid them. Some future extension to either or both documents may do so -
various suggestions have been made as to how to do it, but there is no
agreed method yet.

Nevertheless, people will and do do it, and try to construct a References
header to suit. In fact, if this is done sensibly, existing threading
agents will produce a tolerable behaviour (by which I mean that they will
not list an article as available for reading earlier than any of its
precursors).

In my suggested text for the semantics of the References header, I tried
to word it so as to afford the maximum flexibility for such future
extensions, whilst always ensuring correct behaviour in the single
precursor case.

>does the apperance of References header mean, from a READER perspective?

I once coined the term "pseudo-followup" just for use in our discussions
in this WG (not with any intent of using that term in any document). I was
rewarded with the usual multi-page rant from John :-( .