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

       /FRAME=n

    Specifies the number of data bits that the terminal driver
    expects for every character that is input or output. The value of
    n can be from 5 to 8. The default value depends on the settings
    for the terminal established by the /PARITY and /EIGHTBIT
    qualifiers.