Administrative inquiry procedure requires show-cause notice and opportunity to produce evidence, with power to summon witnesses. Rule 4 requires the Board or adjudicating officer to issue an initial show-cause notice specifying the alleged offence and allowing a minimum period to respond; if an inquiry is directed, a further notice fixing appearance is issued and the alleged statutory provisions are explained. The person may produce documents and evidence, hearings may be adjourned, the Evidence Act need not be followed for taking evidence, and notice or personal hearing may be waived at the person's request. The Board or adjudicating officer may summon witnesses and documents and may proceed in the absence of a non-appearing person after recording reasons.