Subject: Re: Differences between RFC 2822 and Usefor (fwd)

From: John Stanley <[email-masked]>
Date: Wed, 20 Apr 2005 17:24:47 -0700 (PDT)

"Charles Lindsey" <chl@xxxxxxxxxxxxxxxx>:

>There has been no WG decision to
>change the requirement for a References header in followups.

Not according to USEFOR-03.

>Our Chair has
>taken the view that Usefor is not the place to say it, but that Usepro IS
>the proper place (and indeed there is already a corresponding MUST in
>Usepro, though it may need a little more amplification).

USEFOR-03 says it is defined as found in RFC2822, and is optional. 
Optional means "not mandatory". There is no MUST.

>But in that case, I will have to find somewhere in Usepro to say that the
>References header MAY also be used in other cases such as multipart FAQs,

If it is optional, then it is optional. You don't need to say it MAY be 
used when USEFOR-03 already says it may be used.

Like I already said, once you remove the ability to detect followups by 
making References optional, it doesn't matter when it may or may not be 
used. In fact, it may be used anytime (that's what "optional" means), even 
apparently when there is nothing at all for it to convey.

By changing the requirement for References, we've solve a whole passle of 
things that should be be CHANGED BACK to the way they were before you 
decided to take it upon yourself to change them. Like "non-followups MAY 
contain" References headers, which, despite your repeated claims to the 
contrary, is a major change that nobody asked for.

>News readers that try to do threading care very much if it is missing.

That is not an interoperability issue, and you know it. It doesn't cause
the news reader to break, unless it is a VERY poorly designed news reader.
How does it deal with non-followups today, which do not contain References
headers, or broken followups, which also do not contain them, if they
cannot deal with any article tomorrow that does not contain one? If they
break today, they are patently broken and need to be fixed. I know of none 
that are that broken. Do you?

And, by the way, it's software. Until it gains sentience, it doesn't care 
about anything.

>No, the requirement has not gone.

Read the draft-03. It is gone. Explicit language that makes References 
optional. "As defined in RFC2822". No MUST. A MUST that doesn't exist is 
not a requirement.

>The mandate in question is already in USEPRO. And always has been.

But is missing completely in USEFOR, where the header is defined. 

It's gone. It's time to stop pretending that it's there, or that it wasn't 
a deliberate change to remove it. I'm ok with it gone; why are you 
suddenly trying to say that it needs to be put back? You didn't say that 
prior to my commenting on it, it must have been ok -- you had ample time 
to comment on the draft prior to my speaking up, and did not.

---

From: Russ Allbery <[email-masked]>
Date: Wed, 20 Apr 2005 17:56:41 -0700

John Stanley <[email-masked]> writes:

> USEFOR-03 says it is defined as found in RFC2822, and is
> optional. Optional means "not mandatory". There is no MUST.

I think it's obvious that the References header has to be optional in that
sense, since you can construct a well-formed Usenet message that doesn't
have a References header.

I'll repeat my earlier suggestion here, which is to simply define
followups in such a way as to say that if something doesn't have a
References header, it's not a followup.  That neatly avoids the whole
issue without needing to worry about MUSTs and SHOULDs.  It becomes a
definitional issue.  If it doesn't have References, it's not a followup.

> used. In fact, it may be used anytime (that's what "optional" means),
> even apparently when there is nothing at all for it to convey.

> By changing the requirement for References, we've solve a whole passle
> of things that should be be CHANGED BACK to the way they were before you

Well, to be fair, I think it's a reasonable way of dealing with the issue.
I'm not sure if that means I was asking for it, but I can see the logic
behind it.

The way I look at this, there are two separate issues that we keep mixing
together:

 * What a news reader should do when constructing a posted reply to a
   particular post.

 * How a news reader should display messages with References headers.

The former is what we mean by a followup, and by definition it has to
build a References header.  If it doesn't, it's doing something other than
posting a followup.

The latter is a separate issue, a UI issue.  It is expected that messages
connected by References will be shown in a thread, subject to various user
configuration and choices like whether changing the Subject should result
in a separate thread in the user's display (something that should be a
configuration option, not something the standard should be mandating
either way, as there are people who prefer it both ways and there is no
interoperability issue).

There are various reasons why sometimes people like to connect messages
that are not posted replies to each other, and that do not, or only barely
do, fit into the notion of a followup.

I don't think there's really anything else we can say that's more specific
than that.

-- 
Russ Allbery ([email-masked])             <http://www.eyrie.org/~eagle/>

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From: Sebastian Brocks <[email-masked]>
Date: Thu, 21 Apr 2005 11:45:17 +0200

> I don't think there's really anything else we can say that's more specific

I agree.

greetings, Sebastian

---

From: "Charles Lindsey" <[email-masked]>
Date: Thu, 21 Apr 2005 15:55:38 GMT

>Optional means "not mandatory". There is no MUST.

No, USEPRO-03 does not say it is optional. It is silent on the issue (and
our Chair confirms this by saying that RFC 2822 contains both format and
protocol material, and so if you want to see whether some protocol
material in RFC 2822 still applies, then you have to look at USEPRO). I am
not sure I like that way of looking at it, but it is what our Chair says
he wants.

-- 
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: Alexey Melnikov <[email-masked]>
Date: Sun, 24 Apr 2005 16:16:28 +0100

>definitional issue.  If it doesn't have References, it's not a followup.
I fully agree.

>I don't think there's really anything else we can say that's more specific
I agree. And my guess is that RFC 2822 says so little on the subject 
exactly for the same reasons.