I'm indebted to Spartak for enabling me to observe that my earlier response has prompted at least one professional to discard his pseudonym
Well I'll come clean also.
My nick is sort of semi-pseudonym, my real name is Jarkko Lehto
and I live in Finland.
"Yarko" is the correct spelling of my first name, I have
adopted that because English-speaking people used to pronounce it
as "char-koh". And L in the end is the first initial of my surname.
Who's next?