D. J. Bernstein wrote:
The Subject line ends up being created by somebody, encoded as per RFC
2047, decoded for editing in a followup, encoded again, decoded again
for editing in someone else's followup, etc.
The second encoding often has very different bytes from the first.
What is "very different" (vs. "different") supposed to mean?
If the Subject field is edited, it obviously will (except for the
special case of a null effect) have different bytes from the original.
What is your point (assuming that there is one)?