This tree holds the concatenation of the navigation elements of all the deployed topology.xmls. A mirror of the navigation-element in the topology.xml. IDREF has been replaced by a string. Mapping of an application entity to a window in a layout. If no window is specified the application entity applies to the entire LayoutElement The Parent Tree element allows the instance document creator to specify the parent node and position under the parent node where the current navigation element is to be merged. The parent node need not be part of the current instance document, but the document author should ensure that the parent node is defined in the Portal before requesting the merge. If a requested parent node does not exist, the node will be merged at the bottom of the navigation tree. Ordinals are non negative numbers that can be optionally defined while requesting to be merged under a particular parent node. They determine the relative order of nodes under a particular parentTree. If no ordinal is specified, the nodes will be merged in the deployment order under the specified parent. The Page Params element allows the instance document creator to specify the page paramters to be used while rendering the page. Two types of page paramters can be specifed, render-param and page-header. redner-params will be passed as RenderParamter to all portlets on that page while rendering page. page-header value will be added to HTML Head tag of the rendering page. RenderParameter defined by name/value pair will be passed to all portlets as RenderParameters on a page being rendered.