Acknowledgment (in a representative capacity):. 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. An Illinois notary acknowledgment form certifies the authenticity of signatures inscribed on a legal document. This instrument was acknowledged before me on ______(date) by. (name of person acknowledged.) (Seal). The Illinois Notary Acknowledgement form is a vital document that officially recognizes the authenticity of signatures on legal documents. An Illinois notary acknowledgment form is a written authentication from a notary that the signature on a document belongs to the signer. This 5-step guide will teach you how to notarize a document that requires an acknowledgement (the most common notarial act). This article and video will show Notaries to fill out each part of a notarial certificate, and common mistakes to avoid.