Cyrus Daboo <daboo(_at_)cyrusoft(_dot_)com>
Yes indeed! I've already seen instances of a client that emits
'Thread-Topic' and 'Thread-Index' headers that I can't find described
anywhere. These are clearly meant to be an attempt to do some form of smart
message threading, which is fine except that it doesn't use In-Reply-To or
References, which is what rfc2822 suggests. So is this an attempt to
deprecate the use of In-Reply-To and References? This illustrates Keith's
point: should someone be allowed to register a header and state in the
description that this is meant to deprecate an IETF standard header?
Mail-Reply-To seems like the ideal example for that question.
--Arnt