Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!cs.utexas.edu!uunet!talos!kjones
From: kjones@talos.uucp (Kyle Jones)
Newsgroups: news.admin
Subject: Re: Tired of bogus subject lines?
Summary: can't use In-Reply-To, may not contain a message-id
Keywords: In-Reply-To: Reference
Message-ID: <1989Sep19.140057.29912@talos.uucp>
Date: 19 Sep 89 14:00:57 GMT
References: <2454@auspex.auspex.com> <13666@well.UUCP> <1533@isaak.UUCP>
Reply-To: kjones@talos.uu.net
Lines: 27

Jef Poskanzer writes:
 > I suggest that one reasonable way to have reference-following handle
 > gatewayed groups is to ignore them.  Let it break on 3% of the articles.

Dieter Woerz writes:
 > You could even reduce the number of articles without reference-line
 > in gatewayed groups, when the gatewaying software tries to use the
 > In-Reply-To header line, which I think most UAs generate, in mailed
 > postings.

In-Reply-To is not a reliable reference source because

 1. It is an optional header.
 2. It is not required to contain the message-ID of the message being
    replied to.

I've have received many pieces of mail that have an In-Reply-To header
that does not contain a message-ID.

The real solution is to for mail user agents to support the more rigid
RFC 1036 definition of References.  (References has the same status as
In-Reply-To in RFC 822, and this is not enough.)  So if any authors of
MUAs are listening, please make your mailer support References in a
future release.  Every little bit helps.

kyle jones   <kjones@talos.uu.net>   ...!uunet!talos!kjones
"Aye, and if my grandmother had wheels, she'd be a wagon!"