3-5.3 Formally Designate COR The CO will prepare a detailed COR Letter of Appointment that contains, at minimum, the following key information for each appointee: Contract identification. Roles and responsibilities. Recordkeeping duties. Delegated contract management duties. The appointment is made official when the letter of appointment is signed by the CO and countersigned by the COR, ensuring full understanding and acceptance of the position. Suppliers are responsible for notifying the CO when they believe that the COR is not acting within the meaning of established responsibilities, duties, and limitations. Appointments remain in effect until: The contract is completed or CO revokes the appointment. The COR resigns from the Postal Service. The COR is reassigned to a new position.