From: keld(_at_)dkuug(_dot_)dk (Keld J|rn Simonsen)
Subject: Re: CTE:
Date: Thu, 15 Dec 1994 22:28:01 +0100
I think that was Patrik. Perhaps others too. Personally,
I avoid QP (quoted-printable) whenever possible. It seems to be best
suited to files that are "mostly text" or "mostly 7-bit clean".
If you want to send something like a GIF or an executable, or even a
spreadsheet, I would strongly recommend Base64 instead.
QP is not really useful, as the environments where I think it was
intended for, Europena languages with at large portion of the
letters in ASCII, it is still unreadable. We got a number of complaints
from our customers until people stopped sending out QP. It is
only quite occasional now that we QP messages here in my Danish
environment.
This is just FYI.
Q encoding(not QP encoding) is usefule for ISO 2022 JP. Because ISO
2022 JP consists of US-ASCII and JIS X 0208, we usually mixed English
and Japanese in a sentence.
Consider the case people want to insert "Japanese English Japanese"
words into a header field( e.g. JAPANESE_NAME Kazuhiko Yamamoto
JAPANESE_ORGANIZATION into From: field.)
If we use B encoding, the result is as follows;
"=?iso-2022-jp?B?GyRCOzNLXE9CSScbKEI=?="
Kazuhiko Yamamoto
"=?iso-2022-jp?B?GyRCQGhDPEJnM1gbKEI=?="
Note that many Japanese mail readers separate English and Japanese,
then encodes only Japanese just for English readability.
If we use Q encoding, the result is as follows;
"=?iso-2022-jp?Q?=1B$B;3K\\OBI'=1B(B_Kazuhiko_Yamamoto_=1B$B(_at_)hC<Bg3X=1B(B?="
Thus I think Q encoding has two advantages:
(1) We don't have to separate English and Japanese if the result is
short enough for header length limitation.
(2) The result of Q encoding is shorter than B encoding in many cases.
In this point of view, the following statement of RFC 1522 is
inappropriate, I feel.
---
4. Encodings
Initially, the legal values for "encoding" are "Q" and "B". These
encodings are described below. The "Q" encoding is recommended for
use when most of the characters to be encoded are in the ASCII
character set; otherwise, the "B" encoding should be used.
---
--Kazu