Adds license information for a prereq package, should only be used when unable to add the license attributes to the package directly. Extensibility point in the WiX XML Schema. Schema extensions can register additional elements at this point in the schema. Id of the target package. Source file of the license. May not be used with LicenseUrl. Source url of the license. May not be used with LicenseFile. Extensibility point in the WiX XML Schema. Schema extensions can register additional attributes at this point in the schema.