# Generating DTD

A [Data Type Definition (DTD)](https://www.w3schools.com/xml/xml_dtd_intro.asp) is required for running [structure validation checks](validating-web-content-files.html) on a web content file. IntelliJ IDEA can scan any XML file for the existing elements and attributes and generate a DTD for it.

## Generate a DTD for an XML file

Procedure:

1. Open the file in the editor.

2. In the main menu, go to `Tools | XML Actions | Generate DTD From XML File`. IntelliJ IDEA inserts the resulting DTD as a section above the first line of the file.

> **Tip:**
> If the Generate DTD From XML File action is disabled, make sure that the XML file is not [marked as plain text](content-roots.html#exclude-files)
>
> and is not in an [excluded directory](content-roots.html)
>
> .

## Convert DTD to XSD

Procedure:

1. Open the `.dtd` file in the editor and select `Tools | XML Actions | Convert Schema...` from the main menu. The Convert Schema File dialog opens.

2. In the Output type area, specify the format for the generated schema. The available options are:

* [RELAX NG - XML Syntax](https://relaxng.org/spec-20011203.html)

* [RELAX NG - Compact Syntax](https://relaxng.org/compact-20021121.html)

* [W3C XML Schema](https://www.w3.org/XML/Core/)

3. Specify the encoding, indentation, and maximum line length.

4. In the Output Destination field, specify where you want the generated schema file to be stored.

5. Optionally:

Click Advanced and specify additional options in the Advanced Conversion Options dialog that opens. For more information, refer to the [RELAX NG official website](https://relaxng.org/jclark/trang-manual.html).

## See also

### Language and Framework-Specific Guidelines

[Style Sheets](style-sheets.html)

### Procedures

[Validating web content files](validating-web-content-files.html)