1. A method comprising: encoding a designator in an attribute of a display object, the display object configured for rendering according to a media rendering format, the media rendering format invokable with a rendering application, the rendering application for generating a rendered display of the display object; inserting the attribute having the encoded designator into a display object in a display list of a media item, the display list including a set of display objects, each display object having attributes, the rendering application responsive to the attributes for rendering each of the display objects in a rendered media item; and the designator causing the display object to be unrenderable by the rendering application and further being indicative of an origin of the media item.