ORS § 545.105
If there are outstanding bonds of the district at the time of the filing of the petition for exclusion, the holders of the bonds may give their assent, in writing, to the effect that they severally consent that the lands mentioned in the petition, or such portion of the lands as may be excluded from the district by order of the board, may be excluded from the district. If the lands, or any portion of the lands, are excluded from the district, they shall be released from the lien of such outstanding bonds. The assent must be acknowledged by the bondholders in the same manner and form as required for a conveyance of land. The acknowledgment shall have the same force and effect as evidence as the acknowledgment of a conveyance. The assent shall be filed with the board and be recorded in the minutes of the board. The minutes, or a copy thereof certified by the secretary of the board, shall be admissible in evidence with the same effect as the assent. The certified copy may be recorded in the office of the county clerk of the county in which the lands are situated.
ORS 545.105