1. The Commission shall verify the sources, their uses and the methods in the inventory referred to in Article 3(1). A verification model, drawn up by the Commission in close cooperation with the expert group referred to in Article 4, shall be used to that effect. The model shall be based on the principles of peer review and cost-effectiveness and shall take into account the delegated acts referred to in the second subparagraph of paragraph 2 of this Article.
2. GNI data shall be reliable, exhaustive and comparable. The Commission shall adopt delegated acts in accordance with Article 7 to supplement the provision laid down in the first subparagraph of this paragraph by defining the list of issues to be addressed in every verification cycle to ensure the reliability, exhaustiveness and highest possible degree of comparability of GNI data, in line with ESA 2010.
3. The Commission shall establish, by means of implementing acts, specific measures to make GNI data more comparable, reliable and exhaustive, based on the list of issues defined by the Commission in the delegated acts referred to in the second subparagraph of paragraph 2 of this Article. Such implementing acts shall be duly justified and in accordance with ESA 2010. Those implementing acts shall be adopted in accordance with the examination procedure referred to in Article 8(2).