the provisions of Article 6 (excluding the provisions amending Article 46, paragraphs (1) and (2) of the Employees' Pension Insurance Act, the provisions amending Articles 11 through 11-3 of the Supplementary Provisions of that Act, and the provision amending Article 13-6 of the Supplementary Provisions of that Act), Article 9, Article 12, Article 15, and Article 17; the provision in Article 20 amending Article 35, paragraph (6) of the Supplementary Provisions of the Act Partially Amending the National Pension Act, etc.; the provisions in Article 21 amending Article 18, paragraphs (1) and (2) of the Supplementary Provisions of the Act Partially Amending the Employees' Pension Insurance Act, etc.; the provisions of Article 25; and the provisions of Articles 19 through 28, 35, and 36 of the Supplementary Provisions: April 1, 2003;