Excerpts from internet.ietf-822: 17-Sep-91 Re: New-ish idea on non-asc..
Ned Freed(_at_)hmcvax(_dot_)claremo (4148)
I agree completely with Bob on this too. In proposing that mnemonic encoding
be
used in headers, we are in a position to make NO changes to existing header
syntax. No change at all, period. The only, repeat ONLY, change would be to
the
semantics applied to headers when they are DISPLAYED. And this change would
only apply when a new (preferably never before used) header line is present.
I guess my concern with the "just-use-mnemonic" scheme is simply that
the implications for 822 header fields don't appear to have been fully
thought out. In particular, from the August draft on mnemonic it is
kind of hard to figure out quickly which characters are permitted, since
that has been spun off to a separate document that I've lost my copy of,
but an earlier (May) draft suggests that the following characters all
may actually appear as part of mnemonic encodings:
! > ? - ( : , _ " / ; <
Now, I don't have to tell any of the readers of this list that placing
these characters inside certain 822 headers will cause disasters. If
the mnemonic version of my name includes all of these characters, for
example (because my middle name is really S! > ? - ( : , _ " / ; < -- I
just use "S." as a shorthand because of the problem it causes for mail!)
then consider the following, which might replace the "From" header on
the message you are now reading:
From: "Nathaniel S! > ? - ( : , _ " / ; < Borenstein"
<S!>?-(:,_"/;<@my.host.name> (S! > ? - ( : , _ " / ; <)
I doubt that there is a parser in the world that will be able to do
anything useful with this. Even the comment is dubious. Now, I don't
think anyone's seriously proposing that this be allowed, but I haven't
seen anything that indicates that this has all been thought out well
enough.
I wouldn't want to include this stuff in RFC-XXXX until all these issues
had been better addressed. Meanwhile, though, since people aren't
enthused about any of the alternatives I've proposed, I'd be happy to
just leave non-ASCII headers out of RFC-XXXX entirely. There's no
reason they have to be in the same RFC. A companion RFC to the mnemonic
RFC might be the best place to talk about this. Should we just simplify
things by leaving it out of RFC-XXXX?