Okla. Stat. tit. 40 § 171
Whenever any employee of any public service corporation, or of a contractor, who works for such corporation, doing business in this state, shall be discharged or voluntarily quits the service of such employer, it shall be the duty of the superintendent or manager, or contractor, upon request of such employee to issue to such employee a letter, setting forth the nature of the service rendered by such employee to such corporation or contractor, and the duration thereof, and truly stating the cause for which such employee was discharged from or quit such service, and, if any such superintendent, manager or contractor shall fail or refuse to issue such letter, to such employee, when so requested, or shall willfully or negligently refuse or fail to state the facts correctly, such superintendent, manager or contractor shall be deemed guilty of a misdemeanor and upon conviction thereof, shall be punished by a fine of not less than One Hundred Dollars ($100.00), and not more than Five Hundred Dollars ($500.00), and by imprisonment in the county jail for a period of not less than one (1) month and not exceeding one (1) year: Provided, that such letter shall be written, in its entirety, upon a plain sheet of white paper to be selected by such employee. No printed blank shall be used, and if such letter be written upon a typewriter, it shall be signed with pen and black ink and immediately beneath such signature shall be affixed the official stamp, or seal, of said superintendent, manager or other officer of such corporation or contractor, in an upright position. There shall be no figures, words or letters used, upon such piece of paper, except such as are plainly essential, either in the date line, address, the body of the letter or the signature and seal or stamp thereafter, and no such letter shall have any picture, imprint, character, design, device, impression or mark, either in the body thereof or upon the face or back thereof and any person of whom such letter is required who fails to comply with the foregoing requirements shall be liable to the penalties above prescribed.
Okla. Stat. tit. 40, § 171