What is prohibited if the signer appears mentally incapable of understanding the document?

If the signer appears mentally incapable of understanding the document, a notary public cannot notarize the signature. This is rooted in the principle that for a signature to be validly notarized, the signer must have the mental capacity to understand the nature and consequences of the act of signing. Mental incapacity could impair the signer's ability to make informed decisions about the document, which casts doubt on the authenticity and voluntariness of the signature.

The notary's role is to determine whether the signer is signing willingly and has the competence to comprehend the document’s contents. If there is any indication that the signer cannot grasp this, the notary must decline to perform the notarization. This safeguards against potential fraud and protects both the signer and the integrity of the notary's duties. The requirement for mental acuity ensures that the notarial acts are not being misused or exploited in situations where the individual cannot give informed consent.