On 12/14/94 at 10:17 PM, Kazuhiko Yamamoto
=?ISO-2022-JP?B?GyRCOzNLXE9CSScbKEI=?= <kazu wrote:
Thanks Keith, Rick, Dave, Pete, and Parik.
You are welcome. Unfortuately, I think we may have steered you in the wrong
direction.
I'm very much satisfied with the answer that CTE: 7bit is appropriate
for charset=iso-2022-jp.
I'm not so sure anymore. As you say below:
(1) On page 10, the definition "7bit data" is given as follows;
"7bit data" refers to data that is all represented as short
lines of US-ASCII. CR (decimal value 13) and LF (decimal
value 10) characters only occur as part of CRLF line
separation sequences and no NULs (US-ASCII value 0) are
allowed.
The rules about CR, LF, and NUL also hold for 8bit data, as the draft
continues:
"8bit data" refers to data that is all represented as
short lines, but there may be non-US-ASCII characters
(octets with the high-order bit set) present. As with
"7bit data" CR and LF characters only occur as part of
CRLF line separation sequences and no NULs are allowed.
But RFC 1468, which I quoted earlier, is also clear that the text of an
ISO-2022-JP message may contain:
single-byte-char = <any 7BIT, including bare CR & bare LF...
And that will include NUL as well.
Not really. The single-byte-char production is used to accomodate embedded JIS
X 0201-1976 (ISO646-JP) text, not text in JIS X 0208-1978 or JIS X 0208-1983.
JIS X 0201-1976 is basically just a national variant of US-ASCII, where
backslash is replaced with a Yen sign and tilde is replaced with an overbar.
And JIS X 0208-1978 or JIS X 0208-1983 are actually much more restrictive --
they only employ the printable 94 character subset of ASCII.
So in practice you don't see bare CR and LF or NUL in ISO-2022-JP, and 7BIT
suffices to encode it, just as it suffices to encode US-ASCII.
So it seems that RFC 1468 is in direct disagreement with
<draft-ietf-822ext-mime-imb-01.txt>. This restriction did not appear in RFC
1521. According to <draft-ietf-822ext-mime-imb-01.txt>, *neither* straight
7bit *nor* straight 8bit CTE is legal with ISO-2022-JP if contains bare CR,
bare LF, or NUL.
I think what needs to change here is the definition of the Roman text subset of
RFC1468.
Ned