At 4:01 PM 8/19/93 -0700, Mark Crispin wrote:
Two characters in 8IN7 encoding are special. The backslash (\)
character quotes the next character, which may be either another
backslash (\) or a tilde (~); no other character is valid. The
\\ sequence results in a single backslash, and the \~ sequence
results in a single tilde in the destination stream.
The tilde (~) character applies the high order (0x80) bit to the
next character. For example, the sequence ~A (0x7e 0x41)
results in a capital accented A (0xc1).
But what do you do with (eg) a 76-character line with a half-dozen accented
characters in it?
Does it become 82 characters wide (and so die across some mailers)?
Do you arbitrarily break it at <= 80 chars, with no clues as to reassembly?
Do you give up and go to QP? If so, how do you explain that to your users,
who will view this as rather random behavior.
Some editors by their nature leave trailing whitespace at the end of lines.
That comes out in q-p as lots of =20 sequences, none of which are of any
interest to either the sender or the recipient.
Maybe this is our fault as MUA writers. The spec says that trailing spaces
should be represented as =20; the spec doesn't say that an MUA (note the
*U* there) can't strip them instead, if that's what the user wants us to
do. (It would obviously be out of line for a gateway or other transport
agent to strip them; but a user agent is another story.)
Steve Dorner, Qualcomm Inc.