Oregon Constitution Art. IV § 22

No act shall ever be revised, or amended by mere reference to its title, but the act revised, or section amended shall be set forth, and published at full length. However, if, at any session of the Legislative Assembly, there are enacted two or more acts amending the same section, each of the acts shall be given effect to the extent that the amendments do not conflict in purpose. If the amendments conflict in purpose, the act last signed by the Governor shall control.