(a) A participant may appear in a hearing on her or his own behalf or be represented by an authorized representative.

(b) A person appearing shall file a written notice stating her or his name, address and telephone number, and if an authorized representative, the basis of her or his eligibility and the name and address of the participant on whose behalf she or he appears.

(c) A person may be excluded from a hearing for disorderly, dilatory or contemptuous conduct, provided he or she is informed of the grounds and given an opportunity to respond.