f35e173a_orama_portlet___Wiki___Liferay__Description
[Identifier] overlayUrl [Range / Default Value] URL [Description] 
URL of a (possibly scrambled) transparent GIF image. This image enables arbitrary contours being overlayed to the panorama view. The overlay image is center aligned. Set this variable to the empty string in order to disable the overlay.
Using the panorama portlet - Wiki | Liferay
Description