/sys$common/syshlp/helplib.hlb CC, Run-time functions, [w]clrtobot  *Conan The Librarian (sorry for the slow response - running on an old VAX)

  Curses Screen Management function and macro that erase the contents
  of the window from the current position of the cursor to the bottom
  of the window.  The clrtobot macro acts on the stdscr window.

  Syntax:

       #include <curses.h>

       int clrtobot();
       int wclrtobot(WINDOW *win);