Oregon Revised Statutes Elections § 250.115

(1) The Secretary of State shall number the measures to be voted on in the state at large consecutively and shall not repeat any number in any subsequent election. For each election, the numbers assigned shall begin with the number after the last number assigned under this section at the previous election. The Secretary of State shall number amendments to the Oregon Constitution referred to the people by the Legislative Assembly in the order that the amendments are filed with the Secretary of State, followed immediately in number by Acts of the Legislative Assembly submitted to the people for approval or rejection in the order that the Acts are filed with the Secretary of State, followed immediately in number by initiative or referendum petitions in the order that the petitions are filed for signature verification with the Secretary of State.

(2) The Secretary of State shall number state measures not referred to under subsection (1) of this section consecutively, beginning with the number after the last number assigned under subsection (1) of this section, in the order in which the measures are filed with the secretary.