Public Render URLs are a special type of Render URL as defined by the JSR286 (Portlet 2) specification. They are retained through multiple renders (and re-renders) of a given portlet and other portlets setup to use the shared parameter. This is standard behavior for render parameters in the portal environment. See the JSR286 spec for more info: http://jcp.org/en/jsr/detail?id=286 View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4251933#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...