5 The Regional Assembly may not pass any law to diminish, lessen, or reduce the powers, functions, and shares in the internal revenue taxes of the said local government units as provided by Republic Act No. 7160, the Local Government Code of 1991. SEC. 4. Charters Govern Cities. – All chartered cities within the autonomous region shall continue to be governed by their charters. Nothing in this Organic Act shall be construed as to diminish the powers and functions already enjoyed by these cities. SEC. 5. Customs, Traditions, Religious Freedom Guaranteed. – The beliefs, customs, and traditions of the people in the autonomous region and the free exercise of their religions as Muslims, Christians, Jews, Buddhists, or any other religious denomination in the said region are hereby recognized, protected and guaranteed. The Regional Assembly shall adopt measures to ensure mutual respect for and protection of the distinct beliefs, customs, and traditions and the respective religions of the inhabitants thereof, be they Muslims, Christians, Jews, Buddhists, or any other religious denomination. The Regional Assembly, in consultation with the Supreme Court and consistent with the Constitution, may formulate a Shari'ah legal system including the criminal cases, which shall be applicable in the region, only to Muslims or those who profess the Islamic faith. The representation of the regional government in the various central government or national government bodies as provided for by Article V, Section 5 shall be effected upon approval of the measures herein provided. The Shari'ah courts shall have jurisdiction over cases involving personal, family and property relations, and commercial transactions, in addition to their jurisdiction over criminal cases involving Muslims. The Regional Assembly shall, in consultation with the Supreme Court, determine the number and specify the details of the jurisdiction of these courts.