Oregon Revised Statutes Public Officers and Employees § 242.590

(1) The appointing authority must make a permanent appointment from the list of candidates certified by the board, unless, upon reasons signed in writing by the appointing authority, the board consents to and certifies a new list of candidates. If a person on probation is not dismissed during the probationary period the appointment is deemed permanent.

(2) All persons employed as custodians and assistant custodians in a school district on the date the Custodians' Civil Service Law becomes effective as to such school district shall be permanent employees without examination and shall be so appointed by the board.