This article and video will show Notaries to fill out each part of a notarial certificate, and common mistakes to avoid. An essential element to performing a notarial act is completing the notarial certificate, where your signature and seal will be placed.Ensure notarization to enhance legal validity. Sign the document in the presence of a notary public. The notary will confirm your identity and acknowledge your signature. Some states may have special requirements when notarizing a document granting power of attorney. How do I fill this out? Signing your title is an important step in transferring ownership of your vehicle. Form Not Notarized: Washington law says your power of attorney form is valid when you sign it in front of a notary or in front of two disinterested witnesses.