It appears that Paul Smith <paul(_at_)pscs(_dot_)co(_dot_)uk> said:
So, you should try to make lines no longer than 78 characters, but if
they're longer (but no longer than 998) it's not going to break anything.
Right. If you're supporting EAI with unencoded UTF-8, which you should,
the 998 is octets, not characters which matters since UTF-8 code points
vary from one octet to four.
Obviously if you've got a header field name longer than 998 characters
that you would HAVE to fold but you can't, then you've got a problem -
in more ways than one.
No kidding. In practice it appears that systems that add giant private
headers (Yahoo, er, Oath, er, Veriz, er, Apollo, we're looking at you)
tend to make them blocks of opaque hex or base64 that ignore spaces so
they can fold them as needed.
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