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

       /PARITY[=option]
       /NOPARITY (default)

    Controls whether the terminal passes data with only odd or even
    parity, where option equals ODD or EVEN. If you specify the
    /PARITY qualifier without an option, the value defaults to EVEN.