A more thorough explanation:

An attestation clause is a provision found at the end of a legal document, such as a will, that is signed by witnesses. It confirms that the document was executed properly and meets all the legal requirements. The clause serves as evidence of the facts within the document and can be used to prove its validity.

For example, in the context of a will, an attestation clause confirms that the will was signed by the testator (the person making the will) in the presence of witnesses who also signed the document. This creates a presumption that the will was executed properly and that the signatures are genuine.

While attestation clauses are not necessary for the valid execution of a will, they are customary and can be helpful in avoiding disputes over the validity of the document. However, the presumption created by an attestation clause can be challenged with evidence that shows the witnesses did not follow the proper procedures or that the information in the clause is incorrect.

For example, if it can be shown that the witnesses did not actually witness the testator signing the will or that they did not read the attestation clause before signing it, the presumption of proper execution created by the clause will be destroyed.