The <x:forEach> tag in JSTL (JavaServer Pages Standard Tag Library) is used to iterate over XML data. Here's an example of how to use it:

<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<%@ taglib uri="http://java.sun.com/jsp/jstl/xml" prefix="x" %>

<x:parse var="myXml">
  <root>
    <item>Item 1</item>
    <item>Item 2</item>
    <item>Item 3</item>
  </root>
</x:parse>


<x:forEach select="$myXml/root/item" var="item">
    - ${item}

  </x:forEach>

In this example, we use the <x:parse> tag to parse an XML document into an object named myXml. We then use the <x:forEach> tag to iterate over the item elements in the XML document.

Within the <x:forEach> tag, we use the select attribute to specify the XPath expression that selects the nodes to iterate over. We use the $myXml prefix to reference the object that contains the XML data. We use the var attribute to specify the name of the loop variable that holds the current item in each iteration.

Inside the <x:forEach> tag, we can use EL (Expression Language) expressions to access the properties of the current item. In this example, we use ${item} to print the text content of each item element.

Note that the <x:forEach> tag can also be used with other XPath expressions to select nodes based on their attributes or parent-child relationships.