(1) Persons requesting an adjudicative proceeding may be represented subject to the following conditions:

(a) A person requesting an adjudicative proceeding may represent himself or herself or may be represented by an attorney who has complied with the admission to practice rules of the supreme court of the state of Washington.

(b) Every attorney representing a person requesting an adjudicative proceeding shall file a notice of appearance with the adjudicative clerk's office upon commencing representation, and shall file a notice of withdrawal of counsel with the adjudicative clerk's office upon terminating representation.

(c) No person requesting an adjudicative proceeding may be represented in an adjudicative proceeding by an employee of the department.

(2) No current or former employee of the department may appear as an expert, character witness, or representative of any party other than the department if the employee took an active part in investigating or evaluating the case or represented the agency in the matter, unless written permission of the secretary is granted.

(3) No current or former employee of the attorney general's office who participated personally and substantially in investigating or evaluating the matter at issue while so employed may represent a party other than the department or otherwise participate in a related proceeding without first having obtained the written consent of the attorney general's office.