Guide to the use of this commentary
The Secretariat Commentary is on the 1978 Draft of the CISG, not the Official Text, which re-numbered most of the articles of the 1978 Draft. The Secretariat Commentary on article 21 of the 1978 Draft is quoted below with the article references contained in this commentary conformed to the numerical sequences of the Official Text, e.g., article 21 [draft counterpart of CISG article 23].
To the extent it is relevant to the Official Text, the
Secretariat Commentary on the 1978 Draft is perhaps the
most authoritative source one can cite. It is the
closest counterpart to an Official Commentary on the
CISG. A match-up of this article of the 1978 Draft with
the version adopted for the Official Text is necessary to
document the relevancy of the Secretariat Commentary on
this article. See the match-up for this article for a
validation of citations to this Secretariat Commentary.
This match-up indicates that article 21 of the 1978 Draft and CISG article 23 are
Text of Secretariat Commentary on Article 21
[draft counterpart of CISG article 23] [Time of conclusion of contract]
PRIOR UNIFORM LAW
1. Article 21 [draft counterpart of CISG article 23] specifically states that which would otherwise have undoubtedly been understood to be the rule, i.e. that the contract is concluded at the moment than an acceptance of an offer is effective [becomes effective] in accordance with the provisions of this Convention. It was thought desirable to state this rule explicitly because of the large number of rules in this Convention which depend on the time of the conclusion of the contract.
2. On the other hand article 21 [draft counterpart of CISG article 23] does not state an express rule for the place at which the contract is concluded. Such a provision is unnecessary since no provision of this Convention depends upon the place at which the the contract is concluded. Furthermore, the consequences in regard to conflicts of law and judicial jurisdiction which might arise from fixing the place at which the contract is concluded are uncertain and might be unfortunate. However, the fact that article 21 [draft counterpart of CISG article 23], in conjunction with article 16 [draft counterpart of CISG article 18], fixes the moment at which the contract is concluded may be interpreted in some legal systems to be determinative of the place at which it is concluded (OFFICIAL RECORDS, p.26).