15. This Article shall be without prejudice to the Commission’s right to adopt and amend the guidelines as laid down in Article 74. It shall be without prejudice to the possibility for the ENTSO for Gas to develop non-binding guidance in the areas set out in paragraphs 1 and 2 of this Article where such guidance does not relate to areas covered by a request addressed to the ENTSO for Gas by the Commission. The ENTSO for Gas shall submit any such guidance to ACER for an opinion and shall duly take that opinion into account.