This Article, now repealed, defined the scope of income subject to the Natural Gas Investment Tax. As per its provisions, taxable income included the gross income from the sale, exchange, or transfer of natural gas, its liquids, and gas condensates, including sulphur and other associated products. It also encompassed any other incidental or non-operational income derived from the taxpayer's principal activity, irrespective of its type or origin. This included income generated from the utilisation of excess energy in a facility subject to the tax. The article was officially repealed by Royal Decree No. M/70 in 2018.