ORS § 226.590
The summons in the action shall be served on all named defendants who, by diligent search, can be found, in a like manner as service of summons in a civil action. Service of summons on named defendants who cannot be found may be made by publication as provided in ORCP 7. Service of summons on the defendants included in the complaint as "all other persons or parties having or claiming any right, title, estate or interest" may be made by publication. The manner of making publication in the case of those defendants designated as "all other persons or parties having or claiming any right, title, estate or interest" shall be the same as provided in the order for publication of summons in the case of named defendants, except that no order shall be required.
ORS 226.590