MIDL recognizes a number of COMand Automation data types, such as BSTR, VARIANT, and SAFEARRAY, and COM handles, such as HMETAFILE_PICT, HENHMETAFILE, HMETAFILE, HBITMAP, HPALETTE, and HGLOBAL. For more information, including the names of the import files needed to use these types, see Marshaling COM Data Types.