When will Form Manager use those information?

[WilCoX]

I see I can fill in
1. Primary Contact Information
2. Shipping Information
3. Billing Information

but in what situation these information will be applied?

BTW, is there a bug filed that the field e.g. Social Security Number is
too American-centric? Can we just have a more general "Citizen ID" instead?
I am from HK and we call it "HKID".