After my child was born the father to my other children sign the birth certificate form despite we both knew he was not the biological father but agreed he would be the legal father for my child. The biological father has been uncontactable since before the birth of my daughter but I do have concerns that if he may one day try to get custody or parental rights. although a DNA test would still need to be confirmed if he is indeed their biological father if then it is determined that he is the biological father and he agrees to sign off all his parental legal rights, is there a form to do such or advice on how I should obtain this to prevent if in future he wants to change this decision