Oregon Revised Statutes Labor and Employment; Unlawful Discrimination § 663.285

(1) Complaints, orders, and other process and papers of the Employment Relations Board or its designated agent issued under this chapter may be served personally, by registered or certified mail, by telegraph or by leaving a copy thereof at the principal office or place of business of the person required to be served. The verified return by the individual so serving setting forth the manner of service is proof of service. The return post-office receipt or telegraph receipt therefor, when registered and mailed or telegraphed, is proof of service.

(2) Witnesses summoned before the board or its designated agent under this chapter shall be paid the fees and mileage provided for witnesses in ORS 44.415 (2). Witnesses whose depositions are taken and the persons taking the same are severally entitled to the same fees as are paid for like services in the courts of this state.