Delegation of powers allows Principal Chief Commissioner to specify and limit Commissioners' jurisdiction under Service Tax rules. Delegation under section 37A read with section 83 delegates the Board's powers under rule 3 of the Service Tax Rules, 1994 to the Principal Chief Commissioner or Chief Commissioner to specify the jurisdiction of Commissioners of Service Tax and Central Excise in appellate and audit roles, and provides that each such Commissioner's jurisdiction is limited to the jurisdiction so specified; the notification includes a commencement date.