Substantial question of law enables appeals to the High Court from appellate tribunal orders, subject to filing rules and condonation. An appeal lies to the High Court from an Appellate Tribunal order where a substantial question of law is involved; such appeals by revenue or assessee require a memorandum precisely stating the substantial question, filing within 120 days with prescribed fee, though the High Court may condone delay for sufficient cause. The High Court shall formulate and decide the substantial question, may consider other substantial questions for reasons recorded, determine issues not decided or wrongly decided by the Tribunal, and apply Code of Civil Procedure provisions as far as may be practicable.