This section and §§12.26-12.33 of this title (relating to Exemption for Coal Extraction Incidental to the Extraction of Other Minerals) implements the exemption contained in §134.004(19)(A) of the Act concerning the extraction of coal incidental to the extraction of other minerals where coal does not exceed 16 2/3% of the total tonnage of coal and other minerals removed for purposes of commercial use or sale.