Article 11 governs the inclusion of the Tax in the advertised price. It requires that the advertised prices of Excise Goods, when those goods are being sold, be inclusive of the Tax, so that the price presented to the purchaser already carries the excise charge rather than adding it at the point of sale. The Article then allows for exceptions, providing that the instances in which prices do not include the Tax will be determined by the Executive Regulation of the Decree-Law. The obligation is enforceable, as failure to display prices inclusive of Tax is a violation listed in Article 22 of the Decree-Law.