The act of attending the execution of a document and bearing witness to its authenticity, by signing one's name to it to affirm that it is genuine. The certification by a custodian of records that a copy of an original document is a true copy that is demonstrated by his or her signature on a certificate.

An attestation is a declaration by a witness that an instrument has been executed in his or her presence according to the formalities required by law. It is not the same as an Acknowledgment, a statement by the maker of a document that verifies its authenticity.

A tutaj przykład z innej strony:

Divorce Certificate Attestation in UAE is the act of witnessing a Divorce certificate by authorised person/persons/Departments/authorities with their official seal and signature. This attestation also confirms that, the specified divorce certificate has been issued by that mentioned department and Seal and signature on that particular divorce certificate is authentic.

Jest to zatem poświadczenie o autentyczności dokumentu i o tym, że obie strony były przy ustalaniu postanowień zawartych w dokumencie.