This guide includes forms and instructions for a letter and affidavit to request that the court register an out-of-state custody order in Texas. This guide tells you how to ask for a custody, visitation, child support, medical support, and dental support order.The links below will explain the process and provide forms for filing your SAPCR. These guides and articles can help you establish, modify, and enforce custody and visitation in Texas family court. The primary form you will need is a "petition" for a suit affecting the parent-child relationship. Filing the Initial Custody Papers. To begin filing for custody of a child in Texas, you must complete and file the appropriate court documents. 1. Fill out the Petition in Suit Affecting the Parent Child Relationship. You are the Petitioner and the other people involved are the Respondents. How do I ask the court to remove it?