The quantity of goods required in the credit may be indicated on an invoice within a tolerance of +/-5%. A variance of up to +5% in the quantity of the goods does not allow the amount of the credit. The tolerance of +/-5% in the quantity of the goods will not apply when:
a. A credit states that the quantity is bot to be exceeded or reduced; or
b. A credit states the quantity in terms of a stipulated number of packing units or individual items.