Assembly: Microsoft.SqlServer.ManagedDTS (in microsoft.sqlserver.manageddts.dll)
Integration Services packages are saved as XML documents and contain information that describes their objects, properties, and settings. When the run-time engine saves a package, the tasks contained by the package are automatically saved, but with only a limited amount of information. This information includes task creation properties and properties of the TaskHost object that wrap the task.
When writing a custom task, you must implement the IDTSComponentPersist interface to allow your custom task to save custom properties and settings in the package XML.