Defines an IIS virtual directory. When this element is a child of WebSite element, the virtual directory is defined within that web site. Otherwise this virtual directory must reference a WebSite element via the WebSite attribute Extensibility point in the WiX XML Schema. Schema extensions can register additional elements at this point in the schema. Identifier for the web application. If the Id is not specified, it will be generated. References the Id attribute for a WebSite in which this virtual directory belongs. Required when this element is not a child of WebSite element. Sets the application name, which is the URL relative path used to access this virtual directory References the Id attribute for a Directory element that points to the content for this virtual directory. References the Id attribute for a WebDirProperties element that specifies the security and access properties for this virtual directory. This attribute may not be specified if a WebDirProperties element is directly nested in this element. References the Id attribute for a WebApplication element that specifies web application settings for this virtual directory. If a WebApplication child is not specified, the virtual directory does not host web applications. Extensibility point in the WiX XML Schema. Schema extensions can register additional attributes at this point in the schema.