Proof of service (Rule 13)

Section 13, Rule 13, of the Rules, which reads:

SEC. 13. Proof of Service. - Proof of personal service shall consist of a written admission of the party served, or the official return of the server, or the affidavit of the party serving, containing a full statement of the date, place and manner of service. If the service is by ordinary mail, proof thereof shall consist of an affidavit of the person mailing of facts showing compliance with section 7 of this Rule. If service is made by registered mail, proof shall be made by such affidavit and the registry receipt issued by the mailing office. The registry return card shall be filed immediately upon its receipt by the sender, or in lieu thereof the unclaimed letter together with the certified or sworn copy of the notice given by the postmaster to the addressee. (Emphasis and underscoring supplied)