Okla. Stat. tit. 40, § 199.3

It shall be unlawful for any person, partnership, agency, firm or corporation, or officer or agent thereof, to recruit, solicit or advertise for employees, or refer persons (excluding employees or persons who are permanent employees of the employer involved in such strike or lockout) to employment, in place of employees involved in a strike or lockout, without adequate notice to such person, or in such advertisement, that there is a strike or lockout at the place at which employment is offered, and that the employment offered is in place of employee involved in such strike or lockout. Laws 1973, c. 165, § 3.