Article R2312-13 of the French Public procurement code
Purchasers may conclude a defence or security contract at provisional prices only in the following cases:1° When, in the case of complex services or services using a new technique and either of an imperative urgent nature or resulting from an emergency crisis situation, or involving major technical contingencies, performance of the contract must begin while it is not yet possible to determine a definitive initial price;2° When the results of…