Appeal against advance ruling provides a time-limited remedy with possible extension and prescribed procedural formalities. An appeal against an advance ruling under section 98(4) lies to the Appellate Authority by the concerned officer, the jurisdictional officer or the applicant. The appeal must be filed within thirty days of communication, subject to a discretionary extension by the Appellate Authority for sufficient cause for a further period not exceeding thirty days, and must be in the prescribed form, with the prescribed fee and verification.