The "X" in XML stands for "extensible," and many organizations benefit from designing or adapting XML structural rules for their own needs. The Darwin Information Typing Architecture (DITA) is an XML language designed to be customized, using a feature called "specialization." XMetaL Author Enterprise is easily configured to work with DITA specializations. You can get up and running with a specialization in minutes, and if you have some knowledge of programming you can also customize XMetaL menus and toolbars for an optimal user experience. In this session, we'll show how to set up XMetaL to work with a realistic example of a specialized DITA document type.