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Re: Compatibility wit Netnews (was I-D ACTION:draft-resnick-2822upd-01.txt)

2007-05-01 09:25:19

In <p06300002c25bc5f3f74b(_at_)[216(_dot_)43(_dot_)25(_dot_)67]> Pete Resnick 
<presnick(_at_)qualcomm(_dot_)com> writes:

On 4/27/07 at 7:02 PM +0000, Charles Lindsey wrote:

Indeed, the Message-ID is the principal feature of RFC 2822 which 
could not be incorporated into Netnews as it stood.

I had a look at the USEFOR doc, and given how complicated msg-id 
syntax still is, I can't say I'm terribly inclined to start adopting 
it. If USEFOR had come to consensus to completely remove the 
no-fold-quote construct, I'd be a little more inclined.

I would have no problem with doing that, and it would pretty well solve
the problem (you would also need to do something about <no-fold-literal>).

Let me recap what the problem is. Essentially, under RFC 2822 as it
stands, '\a' is semantically equivalent to 'a' and agents are at liberty
to change one into the other en route (of course, nobody ever writes '\a'
and agents en route don't do that, but the possibility is there and some
agents do check for those equivalances). Likewise, '"foobar"' is
semantically equivalent to 'foobar'. Additionally, Netnews cannot tolerate
SP or '>' (whether quoted or not) or any NO-WS-CTL.

So abolishing <no-fold-quote> pretty well solves the problem. The reason
USEFOR did not do that is that it did not want to change anything allowed
by RFC 2822 more than was absolutely necessary. So it disallows '\a' and
'"foobar"' but it allows '\\' and '"foo..bar"' - and the syntax that
enforces that is absolutely horrid, as you can imagine (but it works).

But if 2822-bis is prepared to go further than that, then it is fine with
me. The only question is whether people ever (or ever need to) use
<quoted-string>s in <msg-id>s. I looked in all the news articles and
emails on my computer and found no example of it, but my sample is far too
small. So has anyone else seen that in the wild?

But whatever we do, plese let it be normative. If you don't want people to
generate certain things in the future (we don't care what is left in the
obs-syntax), then say so and be done with it.

But things 
like the "dot-doubling" worry me. (For example, as it stands, all of 
the following are still legal msg-ids under USEFOR:

"."@[]
".."@[]
"..."@[]
"...."@[]
"....."@[]
"......"@[]

Yes, those are all ugly, but they are allowed by RFC 2822 and do no harm
in Netnews (except that only one email/article is ever allowed to contain
each of them, because of the globally unique requirement :-) ).

-- 
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: chl(_at_)clerew(_dot_)man(_dot_)ac(_dot_)uk      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