Insurance contracts taken out by the reinsured companies referred to in the first paragraph of Article R. 322-117-1 must indicate, in very conspicuous characters, the name and address of the mutual insurance association which is substituted for the reinsured companies in accordance with the provisions of the same article, and mention the formal undertaking by this company to take the place of the reinsured companies. Compliance with the provisions of Article L. 310-8 is the responsibility of the mutual union.