Element is used to provide a URI to a secondary VAST response. This secondary response may be another Wrapper, but eventually a VAST wrapper must return an <InLine> ad. Version 3 doesn’t limit number of Wrapper redirection, but from version 4, maximum 5 Wrapper VAST redirections are allowed.
Element which is used to specify what the video player should do if the user clicks directly within the video player frame while the ad is being displayed. When a <VideoClicks> element is provided, it contains a single child <ClickTracking> element with URI (or <ClickThrough> in case of VAST Tag).
Element is used to track the clickthrough when the creative file handles the clickthrough.