Advance ruling clarifies GST treatment of proposed or ongoing supplies for registered or registrable persons under the Act. Defines the advance ruling framework: Advance ruling is a decision to an applicant on specified questions about supplies of goods or services being undertaken or proposed by the applicant. The Authority is the Authority for Advance Ruling; the Appellate Authority is the body constituted for appeals. Applicant covers any person registered or seeking registration under the Act, and application means the request made to the Authority under the Act. These definitions delimit who may seek rulings, the institutional decision-makers, and the procedural entry for obtaining determinations.