ietf-822
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Re: New I-D: draft-koch-subject-tags-considered-00.txt

2004-11-30 23:41:12

On Nov 30 2004, Steve Dorner wrote:

I just spoke to a fellow with a very interesting email proxy system 
that unfortunately works by using such []'ed cruft in subject fields. 
I suppressed my gag reflex, because I understood why he was doing it. 
Most current MUA's hide all headers except a specific few, so if you 
want to communicate anything to the end user, the only way you have 
to do it is by scribbling on those few visible fields.  Or in the 
body, which is even worse.  Gone are the days when you could add a 
header and expect anyone to see it.  So, list processors aside, I 
think we're going to see more of this and not less.


This sounds like something that POPFile also does (which is a statistical
classifier proxy for POP3 and SMTP, reads incoming mail and tags it
according to one of a number of categories, then passes it on. The 
MUA reads the tag and performs actions on the message).

FWIW, I happen to know that the reason [] is added to the subject in that 
particular case is because Outlook Express doesn't allow automatic filing 
of messages based on arbitrary header fields, but can trigger rules
based on words in the subject. Other mail readers are supposed to use
X-POPFile-something. I believe OE is the only braindead MUA of this kind.
 
My MUA ignores such text when doing subject comparisons.

Re: foo
foo
Re[2]: foo
[mydumblist] foo

are all considered equal.  A further step that would probably be 
interesting would be to simply remove such strings from subjects 
displayed in message lists.

Could this be generalized as a recommendation to MUA's?  I dunno.  It 
seems like a feature that's useful a lot of the time, and harmful 
occasionally (eg, when there is real information inside []'s for some 
reason).


You can never distinguish a machine added [] tag from a parenthesis 
inserted by a human. In fact, POPFile is a good example, because the 
contents of the [] can be literally any string the user wants to insert
as a category label. So your MUA would have to query POPFile for the 
list of category strings used or ask the user etc.
 
I personally wouldn't be opposed to amending 2822 to declare that [] 
are comment indicators in subject fields.  I know that sins against 
the holy writ, but oh well...

If a MUA did consider [] as a comment, wouldn't that break "Re[2]:
foo" parsing ?

Laird Breyer.