Keith didn't mention the other option, of which he is also aware, which
is to add the special "_" rule to the MIME quoted-printable spec.
Sorry, but I think this is not too good. It's unnecessary and makes
quoted-printable less readable, contrary to one of its goals. I don't
mind the underscore rule in the header-encoding, since the header already
requires special processing to deal with all the =? ? ? ?= stuff. This
special handler can also deal with underscores and spaces. And the
underscores do buy a little readability here (and every little bit helps).
And really, if the underscore rule is optional in the body and required in
the headers, that's not very different from having two (very similar)
encodings.
Well, I can live with any of these also, with a very mild preference for
the underscore rule in Q only.
By the way, Happy New Year.
Jim