The Board may by order ask any person to appear as respondent in an investigation proceeding. This order shall name those persons to appear as respondents, shall state the purpose of scope of their appearance, shall state the time and place of the hearing, and shall be served on respondents either by Certified mail, return receipt requested, or personally by an employee of the Board or any officer authorized by law to serve process of the District Courts.
253 Neb. Admin. Code, ch. 12, § 003