ORS § 241.250
The commission shall prepare and keep a register for each grade and classification in the classified civil service of all persons whose general average standing upon examination for such grade or classification is not less than the minimum fixed by the rules of the commission, and who are otherwise eligible. Such persons shall take rank upon such register, as candidates, in the order of their relative excellence, as determined by examination and investigation. Candidates of equal standing shall take rank upon the register according to the order in which their applications are filed. The commission may, by rule, provide for striking candidates from the list after they have remained thereon for a specified time, and may limit the number of times the same candidate shall be certified to the appointing power.
ORS 241.250