Although all X.509 certificates use similar methods to assure encryption, authentication, and integrity, they vary significantly in the information they include about the identities that they secure. A useful way to categorize certificates is by the method used by the certificate authority (CA) to validate the subject information included in the certificate: Domain Validation (DV) is the lowest level of validation, and verifies that whoever requests the certificate controls the domain that it protects. Organization Validation (OV) verifies the identity of the organization (e.g. a business, nonprofit, or government organization) of the certificate applicant. Individual Validation (IV) verifies the identity of the individual person requesting the certificate. Extended Validation (EV), like OV, verifies the identity of an organization. However, EV represents a higher standard of trust than OV and requires more rigorous validation checks to meet the requirements set by the CA/Browser Forum.