VMS Help DEFINE, /FORM, Qualifiers, /LENGTH  *Conan The Librarian (sorry for the slow response - running on an old VAX)

       /LENGTH=n

    Specifies the physical length of a form page in lines. The
    default page length is 66 lines, which assumes a standard page
    length of 11 inches with 6 lines of print per inch. The parameter
    n must be a positive integer greater than zero and not more than
    255.

    The print symbiont sets the page length of the device equal to
    the form length. This enables the driver to compute the number of
    line feeds for devices lacking mechanical form feed.