Business entities offering gift coupons shall issue uniform invoices according to the following:
1. Goods coupons: Where the coupon states a fixed amount of goods for which a coupon may be converted, an uniform invoice shall be issued upon selling of such gift coupons.
2. Cash coupons: Where the coupons only indicate the cash amount to be converted into for exchange of goods, the uniform invoice shall be issued upon the conversion of coupon into goods.
Where the cash coupons under subparagraph 2 of the preceding paragraph indicate an agreement with other specific business entities for the conversion of coupons into goods, the uniform invoice shall be issued by the business entities making the conversion upon such conversion transactions.