TITLE: Convention of digit grouping after decimal point
QUESTION [8 upvotes]: I read that different cultures have different ways of grouping digits before the decimal point for readability e.g. 1234567890 can be grouped as 1 234 567 890 (English), 12 3456 7890 (Chinese) or 1 23 45 67 890 (Indian), but is there an established convention for grouping digits of a real number after the decimal point for readability e.g. should 3.14159265358979 be grouped as 3.141 592 653 589 79, 3.14159 26535 8979 or something else?

REPLY [2 votes]: One thing I found is the Swift programming example about decimals Numeric Literals
let oneMillion = 1_000_000
let justOverOneMillion = 1_000_000.000_000_1