Article R524-4 of the French Code of civil enforcement procedures
A creditor who obtains a writ of execution recording the existence of his claim shall serve on the debtor a conversion deed containing, on pain of nullity : 1° A reference to the writ of attachment; 2° A reference to the writ of execution; 3° A separate statement of the sums to be paid in principal, costs and accrued interest, together with an indication of the rate of interest; 4°…