<preference>
    <name>any name</name>    
    <value>any value</value>    
</preference>

You can specify any number of preferences with the preference element depicted above. The name and value are application specific and you can specify whatever value you like. To avoid name conflict, it is suggested to prefix the name with your domain name, such as com.poitx.some.another.

The preferences can then be retrieved back by calling the getPreference method of the org.zkoss.zk.ui.util.Configuration class. Notice that each Web application has one configuration, which can be found by use of getConfiguration method of the org.zkoss.zk.ui.WebApp interface.

String value = webApp.getConfiguration().getPreference("org.zkoss.name", null);
if (value != null) {
    ...    
}