Oregon Revised Statutes Occupations and Professions § 676.110

(1) An individual practicing a health care profession may not use the title “doctor” in connection with the profession, unless the individual:

(2) If an individual uses the title “doctor” in connection with a health care profession at any time, the individual must designate the health care profession in which the individual's doctoral degree was earned on all written or printed matter, advertising, billboards, signs or professional notices used in connection with the health care profession, regardless of whether the individual's name or the title “doctor” appears on the written or printed matter, advertising, billboard, sign or professional notice. The designation must be in letters or print at least one-fourth the size of the largest letters used on the written or printed matter, advertising, billboard, sign or professional notice, and in material, color, type or illumination to give display and legibility of at least one-fourth that of the largest letters used on the written or printed matter, advertising, billboard, sign or professional notice.

(3) Subsection (1) of this section does not prohibit: