Service by publication in such cases shall be deemed complete when it shall have been made in the manner and for the times prescribed in this section. Proof of the publication of the notice shall be made by the affidavit of the printer, or his foreman, or principal clerk, or other person knowing the same, and proof of mailing the said copy, or that the place of residence of such defendants or any of them is unknown to the plaintiff, shall be entered by the affidavit of the plaintiff, his agent or attorney. But no judgment by default shall be entered against the defendants so described on such service until proof thereof be made, and approved by the court and filed. Laws 1919, c. 261, p. 373, § 5.
Oklahoma Legal Code