When you generate an IS document type from an XML schema definition that contains derived types and you select the Generate document types for complex types option, Integration Server creates an IS document type for the base type and one for each derived type. If you also select the Register document types with schema type option, Integration Server registers the generated IS document types with the XML schema types. For more information about derived types, see Derived Types and IS Document Types. For more about registration, see Registering Document Types with Their Schema Types.

When IS document types are registered with their XML schema types, Integration Server adds a *doctype field to the IS document type. Additionally, at run time when the pipeline contains a Document field that conforms to the base IS document type, Integration Server adds the *doctype field to the Document field. Integration Server uses the *doctype field when converting IData objects to XML, converting XML to IData objects, and validating IData objects.