plans that would require
flag-day switchover of either gateways or UAs are non-starters.
For this reason, it would be better to leave the gateways as they are.
Instead, the UAs should be altered (not necessarily all on the same
day) so that, when MIME support is added, the program is also made to
check what code the headers are in. I.e. if the header says
"us-ascii", but the "u" is 0xa4 (hex a4), then the program could guess
that it was converted to EBCDIC.
Problems arise when such a UA emits a MIME message; if it emits EBCDIC and
marks it as such the result will be mislabelled if it goes out on the
Internet. (And once you start creating such things there's no way to guarantee
that they'll never escape.)
Now, if the UA emitted EBCDIC but labelled it as ASCII the result would be more
reasonable since its fellow EBCDIC UAs can read it by definition and the
gateways will do the right thing through ignorance. This corresponds in my
earlier response to the position of "declare the gateways to be MTAs as far as
MIME is concerned". But there's something a bit unsettling about this approach
in the long term. Mind you, this is the way it is now and it is something I
personally could live with. Whether BITNET can live with it is another matter.
Ned