ietf-822
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Re: New-ish idea on non-ascii headers

1991-09-23 09:20:23
This isn't a big point, I don't think.

Excerpts from mail: 23-Sep-91 Re: New-ish idea on non-asc.. John C
Klensin(_at_)INFOODS(_dot_)M (1467)

``ctext'' would be OK, except that comments (where ctext is used) may be
used in MTA-generated Received: headers.  (An MTA that I wrote years ago
puts comments in its Received: lines.)  Does this mean that all MTAs
must check whether comments are to be encoded before printing comments
in the Received: header, and encode the comment text as required?

One of us is confused here.  As far as I know, the only interaction an 
MTA has with Received headers is to add them--it shouldn't need to 

parse, print,... them at all.  And, since the ASCII subset of mnemonic 
is ASCII, there would not seem to be a need for a flag-day conversion.

If some header says that mnemonic encoding is used for the conventional
RFC 822 fields, and one of them is ``ctext'', then every comment in
every header in the message should be encoded in mnemonic.  If an MTA
handles such a message and would ordinarily add a Received: header with
a comment, then the text of the comment has to be encoded in mnemonic. 
Now, for most text, this isn't a problem, but clearly it would be a
problem if the '&' character appeared in the comment without being
quoted.

Maybe I should have said that the MTA-added comments would have to be
*quoted* in mnemonic, and not *encoded* in mnemonic.  But it's the same
thing, really.

                Craig