(4)Where an investment firm deposits funds it holds on behalf of a client with a qualifying money market fund, the units or shares in that money market fund should be held in accordance with the requirements for holding financial instruments belonging to clients. Clients should be required to explicitly consent to the depositing of those funds. When assessing the quality of money market instrument there should be no mechanistic reliance on external ratings. However a downgrade below the two highest short-term credit ratings by any agency registered and supervised by ESMA that has rated the instrument should lead the manager to undertake a new assessment of the credit quality of the money market instrument to ensure it continues to be of high quality.