A Data Type Definition (DTD) is required for running structure validation checks on a Web content file. PhpStorm can scan any XML file for the existing elements and attributes and generate a DTD for it.
To generate a DTD for an XML file
- Open the desired file in the active editor tab.
- On the main menu, choose Tools | XML Actions | Generate DTD From XML File . The resulting DTD is added as a section above the first line of the file.