Keith Moore writes:
Your argument is irrelevant because it assumes that is some value
in the type 2 approach. There is not.
[ ... ]
It is pointless to choose a strategy that creates an extra header
which adds no value.
Do you want another disaster like 8BITMIME? If not, you should be more
careful in your cost-benefit analyses.
Reader strategy 1 interferes with many existing messages. Reader
strategy 2 does not. Many implementors prefer strategy 2 over strategy 1
for exactly this reason.
You're advocating another strategy. Your strategy entails certain risks
that aren't present in strategy 2. It's _possible_ that the resulting
damage is so small that it is outweighed by the tiny costs of an extra
header field; but the necessary studies have not yet been performed.
Kletnieks gave an example of a situation that's difficult to handle with
strategy 2. But the same situation is just as difficult to handle with
strategy 1, and with your strategy.