##### 3.2.2.4.17 Phone Contact with DNS CAA Phone Contact Confirm the Applicant's control over the FQDN by calling the DNS CAA Phone Contact’s phone number and obtain a confirming response to validate the ADN. Each phone call MAY confirm control of multiple ADNs provided that the same DNS CAA Phone Contact phone number is listed for each ADN being verified and they provide a confirming response for each ADN. The relevant CAA Resource Record Set MUST be found using the search algorithm defined in RFC 8659 Section 3. The CA MUST NOT be transferred or request to be transferred as this phone number has been specifically listed for the purposes of Domain Validation. In the event of reaching voicemail, the CA may leave the Random Value and the ADN(s) being validated. The Random Value MUST be returned to the CA to approve the request. The Random Value SHALL remain valid for use in a confirming response for no more than 30 days from its creation. The CPS MAY specify a shorter validity period for Random Values. **Note**: Once the FQDN has been validated using this method, the CA MAY also issue Certificates for other FQDNs that end with all the Domain Labels of the validated FQDN. This method is suitable for validating Wildcard Domain Names.