As a result of the above discussion and finding that Explanation 2 has not been dealing with the case, which was specifically dealt with by sub- section (11) of section 28 of the Act, that we are of the opinion that the challenge in the writ petition is without any merit. The Explanation removes the doubts and states that even those cases which are governed by section 28 and whether initiated prior to the Finance Bill 2011 receiving the assent of the President shall continue to be governed by section 28, as it stood immediately before the date on which such assent is received. The reference to the Finance Bill therein denotes the Bill by the section itself was substituted by Act 8 of 2011 with effect from April 8, 2011. Prior to this Bill by which the section was substituted receiving the assent of the President of India, some cases were initiated and section 28 was resorted to by the authorities. Explanation 2 clarifies that they will proceed in terms of the amended provision. The position dealt with by insertion of section 28(11) is distinct and that is about competence of the officer. The officers namely those from the Directorate of Revenue Intelligence having been entrusted and assigned the functions as noted above, they are deemed to have been possessing the authority, whether in terms of section 28 amended or amended and substituted as above. In these circumstances, for these additional reasons as well, the challenge to this sub-section must fail. Subject to such conditions and limitations as the Board may impose, an officer of customs may exercise the powers and discharge custom the duties conferred or imposed on him under this Act. An officer of customs may exercise the powers and discharge the duties conferred or imposed under this Act on any other officer of customs who is subordinate to him. Notwithstanding anything contained in this section, an Appellate Collector of Customs shall not exercise the powers and discharge the duties conferred or imposed on an officer of customs other than those specified in Chapter XV and section 108.