(d) propose to the Commission any modification of or addition to Articles 303, 308 and 312, Chapter Three, Chapter Four, this Chapter, the Marking Rules, the Uniform Regulations or other provision of this Agreement as required to conform with any change to the Harmonized System; and
(e) consider any other matter referred to it by a Party, or by the Customs Subgroup established under paragraph 6.
4. Each Party shall, to the greatest extent practicable, take all necessary measures to implement any modification of or addition to this Agreement within 180 days after the Commission agrees on any such modification or addition.
5. If the Working Group fails to resolve a matter referred to it pursuant to paragraph 2(f) within 30 days of such referral, any Party may request a meeting of the Commission pursuant to Article 2007.
6. The Working Group shall establish, and monitor the work of, a Customs Subgroup comprising representatives of each Party. The Subgroup shall meet at least four times a year and on the request of any Party and shall:
(a) endeavor to agree on
(i) the uniform interpretation, application and administration of the provisions of Articles 303, 308 and 312, Chapter Four, this Chapter, the Marking Rules and the Uniform Regulations,
(ii) tariff classification and valuation matters relating to determinations of origin,
(iii) equivalent procedures and criteria for the request, approval, modification, revocation and implementation of advance rulings,
(iv) revisions to the Certificate of Origin,