Re: I-D ACTION:draft-hoffman-utf8headers-00.txt

>> Indeed, the next big problem is how servers and other agents are to
>> recognize whether any of the headers of a message contain any 
>> Non_ASCII.
>> Yes, you could scan the headers of every message looking for an octet
>> > 127, but that is a great expenditure of effort considering that 
>> 99.9% of
>> the world's emails will have pure ASCII headers for several years to 
>> come.
>> Far better to have some indication in the message that it is contains 
>> 8bit
>> stuff (most likely an extra header to say so). Indeed, Mark Crispin 
>> is on
>> record as saying that, if he is to have his arm twisted into having 
>> UTF-8
>> headers in IMAP, he would insist on such a header).
>
> I think such a header is not a bad idea. I don't think it's 
> particularly
> important, but if it helps, why not. As for actually scanning the 
> headers,
> I'm not sure about the 'great expediture'. If you have to scan all
> headers to find the header that says it's UTF-8, doing the > 127 check
> on the side is almost free.

having a single flag to say that fields are in utf-8 is ridiculous - 
first because the fields aren't all generated at the same place, and 
second because (as you point out) you potentially have to scan the 
whole header anyway to find the new header field.

but as far as I'm concerned putting utf-8 in headers is a nonstarter 
anyway.  there's simply no justification for  it.