2015 ORS § 40.350¹
Rule 608. Evidence of character and conduct of witness

(1) The credibility of a witness may be attacked or supported by evidence in the form of opinion or reputation, but:

(a) The evidence may refer only to character for truthfulness or untruthfulness; and

(b) Evidence of truthful character is admissible only after the character of the witness for truthfulness has been attacked by opinion or reputation evidence or otherwise.

(2) Specific instances of the conduct of a witness, for the purpose of attacking or supporting the credibility of the witness, other than conviction of crime as provided in ORS 40.355 (Rule 609. Impeachment by evidence of conviction of crime), may not be proved by extrinsic evidence. Further, such specific instances of conduct may not, even if probative of truthfulness or untruthfulness, be inquired into on cross-examination of the witness. [1981 c.892 §52]