[Email-SIG] Non-string headers

[Matthew Dixon Cowles]

[Barry]
> Rather than relax the values that a header can have, I'm inclined
> to tighten them.  The rule could be that the header value must be a
> Unicode string, or an instance providing a particular interface
> (which by default Headers would implement).  This way, raw 8-bit
> strings would be out (mixing 8-bit and Unicodes is evil anyway :),
> and you could always wrap your values in an instance that supported
> the given interface. Accepting Unicodes would be a convenience for
> the simple case.

That makes sense to me as long as plain 7-bit strings are allowed. I
assume that falls out of what's above, but I don't quite see it.

Regards,
Matt