Excerpt from John O. Honnold, Uniform Law for International Sales under the 1980 United Nations Convention, 3rd ed. (1999), pages 391-392. Reproduced with permission of the publisher, Kluwer Law International, The Hague.
§357 The present article deals with a special type of "gap" in the contract—specifications for the goods which the buyer fails to supply.
"(1) If under the contract the buyer is to specify the form, measurement or other features of the goods and he fails to make such specification either on the date agreed upon or within a reasonable time after receipt of a request from the seller, the seller may, without prejudice to any other rights he may have, make the specification himself in accordance with the requirements of the buyer that may be known to him.
"(2) If the seller makes the specification himself, he must inform the buyer of the details thereof and must fix a reasonable time within which the buyer may make a difference specification. If, after receipt of such a communication, the buyer fails to do so within the time so fixed, the specification made by the seller is binding."
Article 65 was designed to prevent a buyer from escaping from its obligations by refusing to supply missing specifications. Supplying the missing specification by the procedure provided in Article 65 forestalls the contention that the contract is too vague for the measurement of damages (Art. 74) and permits the seller to establish the amount of damages by reselling the goods (Art. 75). When the contrast states a fixed price, rather than a "cost-plus" or similar formula, the parties probably would not intend that the buyer’s specifications should substantially affect the cost. Similarly, the parties probably would not intend that the seller could have wide discretion to decide the characteristics of the buyer’s goods. Consequently, references in the contract and in Article 65 to "the form,[page 391] measurements or other features of the goods" should be construed with sufficient strictness to avoid these problems.
Article  can readily be applied where the contract calls for the selection of goods that the seller has in stock, or even for the manufacture of goods to buyer’s specifications where such goods are readily resalable. More difficult problems may arise when the contract calls for the manufacture of goods to specifications that are so unique that they cannot be resold and the buyer notifies the seller that it can no longer use the goods. If the seller thereafter supplies specifications and manufactures goods that have no substantial value, the seller’s action to recover damages or the full contract price may collide with the rules on mitigation of loss in Article 77, infra at §416. (One who engages in such wasteful production faces commercial and legal hazards that are so serious that extreme cases are unlikely to arise.)
When the buyer fails to supply the missing information the seller "may" but need not act for the buyer. The refusal by the buyer to comply with this requirement of the contract would seem sufficiently serious to authorize the seller to avoid the contract (Arts. 25, 64(1)(a)). The seller also may recover damages which could include "loss of profit" (Art. 74) such as the contribution to the seller’s overhead costs that would have resulted from performance. See §415, infra.[page 392]
FOOTNOTES: Chapter on Article 65
1. This article is substantially the same as Article 61 of the 1978 Draft: "within the time so fixed" was inserted in paragraph (2) at the Diplomatic Conference. SR. 26, paras. 34–39, O.R. 374, Docy. Hist. 595. Cf. ULIS 67.
2. SR. 26 paras. 7–11 O.R. 372, Docy. Hist. 593. Sec Art. 14: "A proposal is sufficiently definite if it indicates the goods..." See Dölle, Kommentar (von Caemmerer) Art. 67 at 9, p. 394 (the provision for supplying missing specifications bars any contention that the contract is void because of incompleteness or vagueness).
3. A contrary view by Knapp, B-B Commentary 478 §2.6, seems to overlook avoidance under Article 64(1)(a). Moreover, the broad statement in Article 60(a) that the "buyer’s obligation to take delivery" includes acts to enable the seller to make delivery, §342, supra, may authorize the seller to give the buyer a Nachfrist notice (Art. 63(1)) fixing an additional period for supplying the specifications; if the buyer fails to comply the seller may be able to avoid the contract under Article 64(1)(b) without proving that the buyer had committed a "fundamental" breach of contract (Art. 25).