VMS Help SET, TERMINAL, Qualifiers, /LFFILL  *Conan The Librarian (sorry for the slow response - running on an old VAX)

       /LFFILL[=fill-count]

    Transmits to the terminal the specified number of null characters
    after each line feed before transmitting the next meaningful
    character (to ensure that the terminal is ready for reception).
    The value must be an integer in the range 0 to 9. The default is
    installation dependent.