Non-impairment of Vested or Acquired Substantive Rights.
Section 99
SEC. 99. Non-impairment of Vested or Acquired Substantive Rights. - Changes made and new provisions and rules laid down by this Decree which may prejudice or impair vested or acquired rights in accordance with other mining laws previously in force shall have no retroactive effect: Provided, That the provisions of this Decree which are procedural in nature shall prevail.