Advance ruling clarifies GST treatment for proposed or ongoing supplies, issued by Authority or Appellate Authority. Chapter XVII defines the advance ruling framework: an advance ruling is a decision by the Authority or Appellate Authority on specified questions relating to supplies of goods or services proposed or undertaken by an applicant; the Authority and Appellate Authority are identified as the bodies constituted for decision and appeal; 'applicant' covers persons registered or seeking registration and 'application' refers to the application made to the Authority under the advance ruling procedure.