(2) Functions involving discretion, experienced judgment or expertise vested by law upon a subordinate agency, control shall be exercised in accordance with said law. SEC. 13. Delegation of Authority. - In accordance with the provisions on specific powers provided in this Code, the Regional Secretary or the head of an agency shall have authority over and responsibility for its operation. He/she shall delegate such authority to the bureau and field directors as may be necessary for them to implement plans and programs adequately. Delegated authority shall be to the extent necessary for efficient and effective implementation of national and local programs in accordance with policies and standards developed by each department or agency with the participation of the Field Directors. The delegation shall be in writing; shall indicate to which officer or class of officers or employees the delegation is made; and shall vest sufficient authority to enable the delegate to discharge his/her assigned responsibility. Chapter 6 Relationship of Government-Owned or -Controlled Corporations and Regulatory Agencies to the Department SEC. 14. Government-Owned or Controlled Corporations. - Government-owned or controlled corporations shall be attached to the appropriate department with which they have allied functions, as hereinafter provided, or as may be provided by executive order, for policy and program coordination and for general supervision provided in pertinent provisions of this Code. In order to fully protect the interests of the government in government-owned or controlled corporations, at least one-third (1/3) of the members of the Boards of such corporations should either be a Regional Secretary, Undersecretary and/or Assistant Regional Secretary or other senior officials of the appropriate departments. SEC. 15. Regulatory Agencies. - A regulatory agency shall be subject to the administrative supervision of the department under which they are placed, except when they are government corporations in which case they shall be governed by the provisions of the preceding section. The heads of regulatory agencies shall submit annually, for the approval of the Regional Secretary concerned, their budgets and work plans which shall be the basis of their day-to-day operations. The regulatory agencies may avail themselves of the common auxiliary and management services of the department as may be convenient and economical for their operations. Chapter 7 Appointments and Qualifications SEC. 16. Qualifications of Regional Secretaries. - The Regional Secretaries shall be citizens of the Philippines, registered voters in the Autonomous Region in Muslim Mindanao, not less than twenty-five years of age, and competent & qualified for the position. At least six (6) of the Regional Secretaries of the Regional Departments shall be members of the indigenous cultural communities in the component provinces and cities of the autonomous region. The Regional Secretaries shall also be residents of the autonomous region for at least five (5) years. SEC. 17. Appointment of and Assumption to Office by Regional Secretaries. - The Regional Secretaries of Departments shall be appointed by the Regional Governor subject to 41