Attestation

Attestation may refer to:
 * Attestation clause, verification of a document
 * Oath of Allegiance (United Kingdom) The date from which the service of a member of the armed forces begins is the date of attestation, on which the oath of allegiance is sworn (though the recruit might not report for training until a later date)
 * Various police oaths in the United Kingdom
 * The process of validating the integrity of a computing device such as a server needed for trusted computing
 * Attested language
 * Testimony