On Nov 30 2004, Keith Moore wrote:
I don't think this is cruft - I think it's useful information that
reasonably belongs in the subject field. what's broken is something
else - perhaps our expectation that all messages in a thread should
have the same subject.
Altering the subject is a hack necessary to achieve the intended
effect in commonly used MUAs, but there is no justification beyond
this I can think of. It shouldn't be encouraged, as once the most
popular mail reading software fix this limitation, it will just
be a convention whose motivation is no longer relevant, but whose
consequences will stay.
Since clearly tagging is somewhat valuable information (and given that
we've entered the information glut age, I think we can expect more
varied tagging in the future, not less), there is still the question
where best to put such tags. With this assumption, here are some thoughts:
There's really two places where such information can go, the body or
Bruce made the case in a previous discussion for inserting such
extra information as an attachment, so that the original message is
For tagging, I think it's better to put such information somewhere in the
headers. For example, if your mail resides on an IMAP server, you'll
typically have access to the headers, but the full body won't be
downloaded until absolutely necessary. So a tag which can assist in
collating messages would be useless anywhere but in the message header.
The subject is a great hack for placing tags, because the Subject: field
is some sort of lowest common denominator among MUAs, it's nearly always
displayed to the user. So putting a tag there ensures the greatest likelihood
that the recipient's MUA will have the facilities needed to access the
tag, and that's why it's the natural field used by taggers.
Looking towards the future, if every potential tagger adds their own
X- header field say, then MUAs will never converge to consistent
similar behaviour, because each such tag would have to be treated
as a special case by each MUA. What's needed is a convention for
tagging which all taggers and MUAs can agree on. Without one, the
least common denominator stays the Subject: field, and therefore it will
continue to be misused.
So it seems to me inevitable that some tagging field (Tagged:,
Processed:, or whatever) must be devised. Perhaps the existing Comment:
field can be used for that purpose? I don't know.