Section 92
SEC. 92. Fixed Taxes and Work Obligations. -Work obligations, special taxes and royalties which are fixed by the provisions of this Decree are considered as inherent in all mining leases granted hereunder, and shall remain at the rates and levels in force at the time such leases were issued. Any increase in the amount or rate of such work obligations, special taxes or royalties shall apply only to mining leases granted subsequent to the effectivity of any such increase.