Through the Three stage (kamba) approach, we will try to compare the following provisions of law: Convention for the International Sale of Goods (CISG) Art. 16 and Uniform Commercial code (UCC) section 2.205. In the first phase called “the descriptive phase”, we are going to try to describe the norms, the concepts but also the institutions of these two provisions.
In America contract rule, the general law -applied by the American Court for sales of Goods- consists in saying that an offer is revocable until it is accepted. Even if the offeror promises not to revoke, the promise is regarded as legally ineffective in the absence of consideration or detrimental reliance.
In 1962, Official text of the Uniform Commercial Code (UCC)-enacted as statutory law in most states- included a firm offer rule in section 2.205. Therefore, this section 2.205 is influenced as the same time by common and individual US States law; and also recognized by the American law Institute and the National Conference of Commissioners on Uniform State law. However, each state is free to adopt or to modify it.
Contrary to UCC section 2.205, the Art.16 is taken from the Convention for the international Sale of Goods (CISG). It is an international treaty ratified by the United States and most of the other leading trading nations in the world except Japan and the United Kingdom. The United Nations Commission on International Trade Law (UNCITRAL) - which drafted the treaty dealing with the revocability of offers-, faced a serious challenge in 1981: it had to take into account the common, civil and socialist law.

In this second part, called “the identification phase”, we are just pointing out the similarities and the differences between CISG Art.16 and UCC section 2.205
Indeed, concerning the similarities, both speak about the revocability of offers and require the same kind of assurance of irrevocability.
However, we can distinguish many differences between