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

  Curses Screen Management function and macro that deactivate the
  video display attributes boldface, blinking, reverse video, and
  underlining within a specified window on the terminal screen.  The
  attributes are represented by _BOLD, _BLINK, _REVERSE, and
  _UNDERLINE.  The clrattr macro operates on the stdscr window.

  Syntax:

       #include <curses.h>

       int clrattr(int attr);
       int wclrattr(WINDOW *win, int attr);