Powers of tax officers: exercise and delegation permitted subject to Board limits; appellate authority confined to its remit. Officers of the Central Goods and Services Tax may exercise powers and discharge duties under the Act subject to conditions and limitations imposed by the Board; an officer may act for a subordinate officer, and the Board or Commissioner may delegate powers to subordinate officers subject to specified conditions. A First Appellate Authority is limited to its own allocated powers and may not perform functions of revenue officers beyond that remit.