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

    Positional qualifier.

    Controls whether DSR uses the ASCII backspace character to
    perform character-by-character overprinting. By default, DSR
    performs line-by-line overprinting.