VMS Help PIPE, Qualifiers, /LOGICAL_NAMES  *Conan The Librarian (sorry for the slow response - running on an old VAX)

       /LOGICAL_NAMES (default)
       /NOLOGICAL_NAMES

    Copies process logical names and logical name tables to the
    subprocess of a command sequence. By default, all process logical
    names and logical name tables are copied to the subprocess except
    those explicitly marked CONFINE or created in executive or kernel
    mode.