Any action, suit, or proceeding may be prosecuted or defended by a party in person, or by attorney, except that the state or a party that is not a natural person appears by attorney in all cases, unless otherwise specifically provided by law. Where a party appears by attorney, the written proceedings must be in the name of the attorney, who is the sole representative of the client of the attorney as between the client and the adverse party, except as provided in ORS 9.310.
ORS 9.320