I totally agree - there's not a roman numeral justifaction for it at all and it's very confusing in normal situations. My understanding is that it comes from f

I totally agree - there's not a roman numeral justifaction for it at all and it's very confusing in normal situations. My understanding is that it comes from financial (specifically trader) jargon and I suspect it probably originated to differentiate it from some other use of "m", but don't know for sure... Maybe someone else knows why it arose?