Excerpts from ext.ietf-822: 2-May-91 character sets Erik M. van der
Poel(_at_)sra (4532)
I think most people would agree that intermediate MTAs should not
modify the contents of messages. Modifications such as character
encoding conversions should only be done by the UAs or by intermediate
nodes (gateways) that have been "authorized" to do so. An example of
such a gateway would be an ASCII<->EBCDIC converter.
These simple conversions can only be easily done if the body of the
message is one big text field. When we start sending documents, rather
than text streams, most MTAs usually won't be able to do the right thing
anyway, because the "text" fields will be embedded in some sort of
document structure, which will probably not be understood by the MTA (I
hope!). It won't be able to *find* the text to convert. I think that
the best we can do is to indicate the codeset being used in the message,
and hope for the receiving UA to do the "right" thing.
Is it reasonable for the MTA to do automatic conversions, say upon
entrance to an enclave, if the Content-Type is "text", and the
Character-Set is "Shift-JIS", and the enclave uses default-character-set
"foo"? Might be an important special case, as the MTA knows where the
text is -- but it seems to be handled well by simply including the
Character-Set header.
Bill