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