Kinoshita-san,
At 10:29 PM 12/7/94, Satoshi Kinoshita wrote:
You mean iso-2022-jp is not conformed to rfc822 without any regard to MIME?
Without Mime, a reciving mail user agent has no way to know that the body
is ISO-2022-jp. With MIME, it does.
In its strictest sense, RFC822 has no concept of "different" body content,
as long as it is 7-bit ASCII. The difficulty, of course, is to try to
define the difference between 7-bit ASCII and something that is 7-bit but
not ASCII.
ASCII defines particular character interpretations for particular bit
patterns. For example, x0D0A is carriage-return, line-feed. While there
is one view that ISO-2022-jp is "on top of" ASCII and therefore conformant
to the RFC822 requirement for ASCII, there is another view which says that
ASCII characters, like 'a', 'b', or 'c', are very definitely NOT the
interpretations for the ISO-2022-jp characters and that therefore,
ISO-2022-jp is NOT conformant.
In writing the above paragraph, I find myself quite unhappy and, perhaps,
confused. But then, that's my reaction to most discussions about character
set.
That is part of the reason that I try to stress the need for using Mime.
Mime makes it possible to add some clarity to this confusion, because it
allows labeling. In other words, I view RFC 822 as being entirely crippled
for use in the broad range of body types -- including the broad range of
languages, characters and character sets -- for which it is now in use.
Mime fixes that.
d/
--------------------
Dave Crocker
Brandenburg Consulting Phone: +1 408 246 8253
675 Spruce Dr. Fax: +1 408 249 6205
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dcrocker(_at_)mordor(_dot_)stanford(_dot_)edu