VMS Help DCE_IDL, ARGUMENTS, -keep  *Conan The Librarian (sorry for the slow response - running on an old VAX)

   -keep file_types

   Specifies which files to retain.  To produce the object modules,
   the IDL compiler first creates C source modules, then invokes the
   target C compiler to produce object modules, and finally, deletes
   the C source modules.  If you do not use -keep, only the object
   modules are saved.

   The file types are as follows:

   none      Does not save the C source or the object modules.  Does
             not invoke the C compiler.

   c_source  Saves only the C source modules. Does not invoke the C
             compiler.

   object    Saves only the object modules.

   all       Saves both the C source and the object modules.