CISG Article 9
(1) The parties are bound by any usage to which they have agreed and by any practices which they have established between themselves.
(2) The parties are considered, unless otherwise agreed, to have impliedly made applicable to their contract or its formation a usage of which the parties knew or ought to have known and which in international trade is widely known to, and regularly observed by, parties to contracts of the type involved in the particular trade concerned.
Article 66 [Contract terms]
The terms of the contract are derived from:
Article 67 [Usages and practices in contracts between traders]
1. In a contract between traders, the parties are bound by any usage which they have agreed should be applicable and by any practice they have established between themselves.
2. The parties are bound by a usage which would be considered generally applicable by traders in the same situation as the parties.
3. Usages and practices do not bind the parties to the extent to which they conflict with contract terms which have been individually negotiated or any mandatory rules of the Common European Sales Law.
Article 68 [Contract terms which may be implied]
1. Where it is necessary to provide for a matter which is not explicitly regulated by the agreement of the parties, any usage or practice or any rule of the Common European Sales Law, an additional contract term may be implied, having regard in particular to:
2. Any contract term implied under paragraph 1 is, as far as possible, to be such as to give effect to what the parties would probably have agreed, had they provided for the matter.
3. Paragraph 1 does not apply if the parties have deliberately left a matter unregulated, accepting that one or other party would bear the risk.
Article 69 [Contract terms derived from certain pre-contractual statements]
1. Where the trader makes a statement before the contract is concluded, either to the other party or publicly, about the characteristics of what is to be supplied by that trader under the contract, the statement is incorporated as a term of the contract unless:
2. For the purposes of paragraph 1, a statement made by a person engaged in advertising or marketing for the trader is regarded as being made by the trader.
3. Where the other party is a consumer then, for the purposes of paragraph 1, a public statement made by or on behalf of a producer or other person in earlier links of the chain of transactions leading to the contract is regarded as being made by the trader unless the trader, at the time of conclusion of the contract, did not know and could not be expected to have known of it.
4. In relations between a trader and a consumer the parties may not, to the detriment of the consumer, exclude the application of this Article or derogate from or vary its effects.
Article 70 [Duty to raise awareness of not individually negotiated contract terms]
1. Contract terms supplied by one party and not individually negotiated within the meaning of Article 7 may be invoked against the other party only if the other party was aware of them, or if the party supplying them took reasonable steps to draw the other party's attention to them, before or when the contract was concluded.
2. For the purposes of this Article, in relations between a trader and a consumer contract terms are not sufficiently brought to the consumer's attention by a mere reference to them in a contract document, even if the consumer signs the document.
3. The parties may not exclude the application of this Article or derogate from or vary its effects.