Article 9 closes Chapter 3 of the Decree-Law on Tax Registration and Deregistration by delegating the operational detail to secondary legislation. It provides that the Executive Regulation of the Decree-Law shall determine the procedures, controls and conditions of Tax Registration and Tax deregistration, and also the rejection of applications for Tax Registration and Tax deregistration. The registration duties imposed by the preceding Articles are therefore applied through the mechanisms laid down in the Executive Regulation, which governs how an application is made, the conditions attaching to it, and the basis on which the Authority may refuse an application for registration or deregistration.