in reply to
binmode STDOUT, ":utf8"; and umlauts
Your own Unicode Advice is a little more strenuous about not using _utf8_on and _utf8_off, which is what :utf8 boils down to.
By rote learning.
Via Genetic memory.
It's provided by my firmware.
I just remember them.
Thirty days hath September
My computer gets it right, usually.
I just ask someone else.
Someone punches me on the first of the month.
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