Русско-англо-русский юридический словарь

This Agreement will become effective when one or more counterparts have been signed by each of the parties and delivered to the other parties, which delivery may be made by exchange of copies of the signature page by facsimile or other electronic transmission. (Law Insider)

A notary certificate is a separate page or document attached to a signature page of a larger document, which contains the legally required wording for a notarization in the state in which the signing occurs. (Quora, Jane Tierney, 14 years as a notary public and certified signing agent)