Well-Formed and Valid XML 目 Wel/-Formed XML allows you to invent your own tags. Valid XML conforms to a certain DTD, or XML schema Relational database Valid XML Well-formed XML from strict Structure to loose Structure 88 Well-Formed and Valid XML † Well-Formed XML allows you to invent your own tags. † Valid XML conforms to a certain DTD, or XML schema . Relational database Valid XML Well-formed XML from strict Structure to loose Structure