(10)Prior express consent by clients should be given and recorded by investment firms in order to allow the investment firm to demonstrate clearly what the client agreed to and to help clarify the status of client assets. However, no legal requirement should be set out in respect of the form in which consent may be given, and a record should be understood as any evidence permissible under national law. Client's consent may be given once at the start of the commercial relationship, as long as it is sufficiently clear that the client has consented to use of their securities. Where an investment firm is acting on a client instruction to lend financial instruments and where this constitutes consent to entering into the transaction, the investment firms should hold evidence to demonstrate this.