Authorisation of central tax officers as proper officers enables central officers to act under state GST rules subject to conditions. Officers appointed under the Central Goods and Services Tax Act may be authorised to act as proper officers for State GST subject to notification-specified conditions; where a State proper officer issues an order he must also issue a corresponding order under the Central Act with intimation to the jurisdictional central officer; initiation of proceedings by a central proper officer bars duplicate State proceedings on the same subject; rectification, appeal and revision of orders by State officers shall not lie before officers appointed under the Central Act.