There'se always been a lot of confusion regarding these abreviations.
ASA
DIN
ISO
GOST
Plus I think the the Japanese had their own at one time.
ASA = American Standards Association
DIN = Deutsches Institut für Normung
ISO = International Standards Organization
GOST = Gosudarstvennyy Standart ( as found on Zenits and Feds LOL )
Actually sensitivity is one of the few American measurements that the world has embraced. The European standard was for the most part DIN. ISO is an agreement by all countries to use a standard form of measurement to avoid confusion. The clock is ticking on the USA and the UK switching to kilometers.
To refer to sensitivity as ISO is a bit ridiculous, you may as well say you were driving at 60 ISO or that you weigh 92 ISO.
But that's how it iis, we've all got used to it I guess.
Well I'm off to heat some water to 100 ISO and enjoy a tea
PP