Appellate Authority substitution clarifies jurisdictional terminology and provides transfer of pending advance-ruling proceedings to new authority. The amendment replaces references to the Authority with the Appellate Authority in section 28F(1), adjusting statutory terminology to reflect an appellate role, and inserts a transitional sub-section providing that pending applications and proceedings before the former Authority for Advance Rulings are transferred to the newly appointed Authority to continue from their existing procedural stage.