I can't tell if the parent is a joke. If not, I should tell you that decimal separator is usually regarded as variable and therefore just part of local represen

I can't tell if the parent is a joke. If not, I should tell you that decimal separator is usually regarded as variable and therefore just part of local representation, in a similar way to time and date formats. Plenty of code is only able to cope with a particular representation, or has bugs around dealing with varying ones.