This value is merged with the UrlTemplate on the Link Type to create the final URL. if there is no URL Template specified on the link type then this should be a full URL, otherwise it will be inserted into the template as the first insertion value for a .NET format string.
Requirements
Target Platforms: Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2