Show-cause notice initiates inquiry, ensuring hearing rights, evidence submission, and power to summon witnesses. Rule 4 requires a show-cause notice specifying the alleged offence and allowing a minimum response period; if an inquiry proceeds, a hearing is fixed where the alleged contravention and relevant provisions are explained and the person may produce documents and evidence. The adjudicator need not be bound by the Evidence Act, may waive notice or hearing on request, can summon witnesses and documents, and may continue proceedings in the absence of the person after recording reasons.