Appointment of custodian: portfolio managers must secure custodial arrangements, with narrow exceptions for advisory and co investment roles. Every portfolio manager engaged in managing or administering securities must appoint a custodian to hold those securities, creating a separation between management and custody functions. The obligation does not apply to portfolio managers who provide only advisory services and is also excluded for co investment portfolio managers, thereby restricting the custodian requirement to managers with discretionary or administrative control over client securities.