# XML Schemas support

## Availability

This is an [Orbeon Forms PE](https://www.orbeon.com/download) feature.

## Working with an XML Schema

The toolbox's "Upload Schema" button under the "Advanced" section allows you to attach an XML Schema to the form. This serves two purposes:

* The schema is used to validate the form data.
* Simple types present in the schema are made available in the Validation Details dialog.

NOTE: Form Builder does not handle imported/included sub-schemas. If you attempt to attach such a schema, a warning message is displayed.