An XML "value," computed by a query expression, may consist of zero, one, or many items, each of which may be an element, an attribute, or a primitive value.

You can configure the Fan Out mediation primitive to fire its output terminal just once or once for each element obtained using a specified XPath expression.

For example, you can configure a message Filter mediation primitive to route messages down one of multiple paths, depending on whether a particular XPath expression holds true.