Authorisation of central tax officers enables them as proper officers under state GST with coordinated orders and exclusive proceedings. Officers appointed under the Central Goods and Services Tax Act may be authorised by State notification to act as proper officers under the State Act subject to specified conditions; orders issued under the State Act must be mirrored under the Central Act with intimation to the central jurisdictional 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-appointed officers do not lie before central officers.