<P> The CISG attempts to resolve the common situation where an offeree's reply to an offer accepts the original offer, but attempts to change the conditions . The CISG says that any change to the original conditions is a rejection of the offer--it is a counter-offer--unless the modified terms do not materially alter the terms of the offer . Changes to price, payment, quality, quantity, delivery, liability of the parties, and arbitration conditions may all materially alter the terms of the offer . </P> <P> Articles 25--88; sale of goods, obligations of the seller, obligations of the buyer, passing of risk, obligations common to both buyer and seller . </P> <P> The CISG defines the duty of the seller,' stating the obvious', as the seller must deliver the goods, hand over any documents relating to them, and transfer the property in the goods, as required by the contract . Similarly, the duty of the buyer is to take all steps' which could reasonably be expected' to take delivery of the goods, and to pay for them . </P> <P> Generally, the goods must be of the quality, quantity, and description required by the contract, be suitably packaged and fit for purpose . The seller is obliged to deliver goods that are not subject to claims from a third party for infringement of industrial or intellectual property rights in the State where the goods are to be sold . The buyer is obliged to promptly examine the goods and, subject to some qualifications, must advise the seller of any lack of conformity within' a reasonable time' and no later than within two years of receipt . </P>

United nations convention on contracts for the international sale of goods citation