# DTD Topic Type Shell Creation Tutorial

This tutorial demonstrates the process of creating a DTD-syntax document type shell.

In this tutorial you will create a document type shell for <topic> that removes the technical-documentation-specific domains and adds a reference to the XML markup domain (defined in Element Domain Specialization Tutorial).

The other tutorials also include instructions for creating shells that integrate the components created in those tutorials. This tutorial shows you the basic process for shell creation, showing both removing existing references and adding new references.