# XML Schemas support

## Availability

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

## Working with an XML Schema

The toolbox's "XML Schema" button under the "Advanced" tab 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.


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://doc.orbeon.com/form-builder/advanced/xml-schema-support.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.