VMS Help CONVERT, /DOCUMENT, CDA Base Service Converters, Text Output Converter, ASCII_FALLBACK  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    ASCII_FALLBACK [ON,OFF] causes the Text output converter to
    output text in 7-bit ASCII. The fallback representation of the
    characters is described in the ASCII standard. If this option is
    not specified, the default is OFF; if this option is specified
    without a value, the default is ON.