For an acknowledgment in a representative capacity: State of Washington. An acknowledgment is one of the most common types of notarial acts, but it often confuses Notaries.Here are 5 steps to performing an acknowledgment. The short-form acknowledgment certificate is used when an individual is signing and acknowledging on his or her own behalf. A Washington notary acknowledgment form is used to officially authenticate a signature on a legal document. Download a notary acknowledgment form in PDF or Word format. This 5-step guide will teach you how to notarize a document that requires an acknowledgement (the most common notarial act). First, you can fill out section C of the notary public application if you are adding the endorsement at the same.