Okla. Stat. tit. 21 § 1561
Every person who, with intent to defraud, forges, counterfeits or falsely alters:
1st. Any will or codicil of real or personal property, or any deed or other instrument being or purporting to be the act of another, by which any right or interest in real property is, or purports to be, transferred, conveyed or in any way changed or affected; or,
2nd. Any certificate or endorsement of the acknowledgment by any person of any deed or other instrument which by law may be recorded or given in evidence, made or purporting to have been made by any officer duly authorized to make such certificate or endorsement; or,
3rd. Any certificate of the proof of any deed, will, codicil or other instrument which by law may be recorded or given in evidence, made or purporting to have been made by any court or officer duly authorized to make such certificate, is guilty of forgery in the first degree.
Okla. Stat. tit. 21, § 1561