Oregon Revised Statutes Elections § 249.712

(1) To complete a nomination, the nominee must accept the nomination.

(2) The acceptance of the nominee may be indorsed upon the certificate of nomination and signed by the nominee, or it may be indorsed by a letter or telegram from the nominee attached to the certificate and filed with it. If the acceptance does not accompany the certificate of nomination, the nominee, at any time after the certificate is filed and before the time for filing nominations for the office has expired, may file an acceptance in the same manner and in the same office where the certificate is filed. The officer with whom the acceptance is filed shall indorse it and attach it to the certificate of nomination to which it refers.