An Acknowledgement of Paternity (AOP) allows parents who aren't married to establish legal paternity. Learn more about the AOP process and how to file.Access Conflict of Interest and Disclosure Forms for Employees, Officials and officers. Access Lobbyist forms. An Acknowledgment of Paternity (AOP) is a legal document that allows parents who aren't married to establish legal paternity. Form for Ordinary Certificate of Acknowledgment. Mail completed form, payment and valid ID to: DSHS - VSS,. P.O. Box 12040, Austin, TX 78711-2040. Downloadable forms for eFiling, Divorces, and Suites Affecting the Parent-Child Relationship, Child Support, Hail Claims, Legal, LegalEase, and Passports. Do I have to complete the Juror Qualification Questionnaire form?