There's absolutely no reason to hard-code the value. That's just bad programming. However you can't expect programmers to predict all possible future compatibi

There's absolutely no reason to hard-code the value. That's just bad programming. However you can't expect programmers to predict all possible future compatibility. In my country VAT has a current rate. That rate can, and has, changed. But we have one rate. Some goods are exempt, but products have a VAT yes/no field. Perhaps in the future the system will change. One possible change is that VAT attracts different % for different products. I'm not predicting that, or coding for it now. VAT rules could change to anything- I can't code against that.