Requests for mutual assistance from foreign judicial authorities shall be executed in accordance with the procedural rules provided for by this Code.
However, if the request for mutual assistance so specifies, it shall be executed in accordance with the procedural rules expressly indicated by the competent authorities of the requesting State, provided, on pain of nullity, that such rules do not reduce the rights of the parties or the procedural guarantees provided for by this Code. Where the request for mutual assistance cannot be executed in accordance with the requirements of the requesting State, the competent French authorities shall inform the authorities of the requesting State without delay and indicate the conditions under which the request could be executed. The competent French authorities and those of the requesting State may subsequently agree on the action to be taken in response to the request, where appropriate by making it subject to compliance with the said conditions.
Irregularities in the transmission of the request for mutual assistance shall not constitute grounds for invalidity of acts carried out in execution of that request.