In Virtuemart (Joomla) some data-fields of the orders, invoices (e-mail and account) and the cart needs extra logic:
1) address fields: only be shown, if they are not empty
2) Coupon-Discount: only be shown, if coupoun code is used
3) Paymentmethod-Discount: only is shown, if it is applicable
here are several cases, 2 category types are possible (with discount = A /without discount = B):
a) orders with only A: Payment-Discount / Coupon-Discount (only if it is used) is calculated and shown
b) orders with only B: Payment-Discount / Coupon-Discount is not calculated and not shown
c) orders with A and B: Payment-Discount / Coupon-Discount (only if it is used) is calculated and shown for A and Payment-Discount / Coupon-Discount is not calculated for B
In the case of 3) and c) a short note has to be shown, that for products of B no discount is given.
And a bug must be fixed: coupon discount on Products of category B is calculated at the moment. In the backend a checkbox is implemented at categories (discount yes/not), Category B is checked as "not". Not only paymentmethod-discount but also coupon-discount mustn't be calculated for products of category B.