Here is my web.xml :

<?xml version="1.0" encoding="UTF-8"?>
<web-app metadata-complete="true" xmlns="http://java.sun.com/xml/ns/javaee"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
                      http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
	version="3.0">

	
	<filter-mapping>
		<filter-name>richfaces</filter-name>
		<servlet-name>Faces Servlet</servlet-name>
		<dispatcher>REQUEST</dispatcher>
		<dispatcher>FORWARD</dispatcher>
		<dispatcher>INCLUDE</dispatcher>
	</filter-mapping>
	
	<filter-mapping>
		<filter-name>MyFacesExtensionsFilter</filter-name>
		<servlet-name>Faces Servlet</servlet-name>
	</filter-mapping>
	<filter-mapping>
		<filter-name>MyFacesExtensionsFilter</filter-name>
		<url-pattern>/faces/myFacesExtensionResource/*</url-pattern>
	</filter-mapping>
	<filter-mapping>
		<filter-name>Pretty Filter</filter-name>
		<url-pattern>/*</url-pattern>
		<dispatcher>FORWARD</dispatcher>
		<dispatcher>REQUEST</dispatcher>
		<dispatcher>ERROR</dispatcher>
		<dispatcher>ASYNC</dispatcher>
	</filter-mapping>

	<filter>
		<display-name>RichFaces Filter</display-name>
		<filter-name>richfaces</filter-name>
		<filter-class>org.ajax4jsf.Filter</filter-class>
		<async-supported>true</async-supported>
	</filter>
	<filter>
		<filter-name>MyFacesExtensionsFilter</filter-name>
		<filter-class>org.apache.myfaces.webapp.filter.ExtensionsFilter</filter-class>
		<async-supported>true</async-supported>
		<init-param>
			<param-name>uploadMaxFileSize</param-name>
			<param-value>20m</param-value>
			<description> Set the size limit for uploaded files.
            Format: 10 - 10 bytes
                    10k - 10 KB
                    10m - 10 MB
                    1g - 1 GB
        </description>
		</init-param>
	</filter>
	
	<filter>
		<filter-name>Pretty Filter</filter-name>
		<filter-class>com.ocpsoft.pretty.PrettyFilter</filter-class>
		<async-supported>true</async-supported>
	</filter>
</web-app>

Here is my simple pretty-config.xml:

<?xml version="1.0" encoding="UTF-8"?>
<pretty-config xmlns="http://ocpsoft.org/prettyfaces/3.3.3" 
               xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
               xsi:schemaLocation="http://ocpsoft.org/prettyfaces/3.3.3
               http://ocpsoft.org/xml/ns/prettyfaces/ocpsoft-pretty-faces-3.3.3.xsd">

    <url-mapping id="list-instances">
        <pattern value="/li" />
        <view-id value="/provisioning/list-instances.xhtml?isfirst=true" />
    </url-mapping>

</pretty-config>