the variables described below.
@end deffn
+@defopt display-buffer-reuse-frames
+If this variable is non-@code{nil}, @code{display-buffer} searches
+existing frames for a window displaying the buffer. If the buffer is
+already displayed in a window in some frame, @code{display-buffer} makes
+the frame visible and raises it, to use that window. If the buffer is
+not already displayed, or if @code{display-buffer-reuse-frames} is
+@code{nil}, @code{display-buffer}'s behavior is determined by other
+variables, described below.
+@end defopt
+
@defopt pop-up-windows
This variable controls whether @code{display-buffer} makes new windows.
If it is non-@code{nil} and there is only one window, then that window