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

       /LOG
       /NOLOG (default)

    Controls whether the DSR Indexing utility displays the name of
    each input file as it is processed and after it is processed, as
    well as the name of each output file created. If there are any
    errors in processing, the RUNOFF/INDEX command sends messages to
    the terminal even if the /NOLOG qualifier is in effect.