/sys$common/syshlp/helplib.hlb DCE_IDL, FILES  *Conan The Librarian (sorry for the slow response - running on an old VAX)

   SYS$SYSTEM:DCE$IDL.EXE
                  IDL Compiler

   SYS$COMMON:[DCE$LIBRARY]
                  System IDL directory for imported files

   SYS$COMMON:[DCE$LIBRARY]NBASE.IDL
                  Predefined IDL types

   SYS$COMMON:[DCE$LIBRARY]file.ext
                  All .idl or .h files that are part of DCE RPC