Article R2112-14 of the French Public procurement code
Contracts with a performance period of more than three months which require for their performance the use of a significant proportion of supplies, in particular raw materials, the price of which is directly affected by fluctuations in world prices, shall include a price review clause including at least one reference to the official indices used to set these prices, in accordance with the provisions of article R. 2112-13. However, contracts…