-specified by the variable @code{appt-display-format}. If the value
-of @code{appt-audible} is non-@code{nil}, an audible reminder is also given.
+specified by the variable @code{appt-display-format}. If the value of
+@code{appt-audible} is non-@code{nil}, an audible reminder is also
+given. In addition, if @code{appt-display-mode-line} is non-@code{nil},
+Emacs displays the number of minutes to the appointment on the mode
+line.
+
+@vindex appt-display-duration
+@vindex appt-disp-window-function
+@vindex appt-delete-window-function
+ If @code{appt-display-format} has the value @code{window}, then the
+variable @code{appt-display-duration} controls how long the reminder
+window is visible for; and the variables
+@code{appt-disp-window-function} and @code{appt-delete-window-function}
+give the names of functions used to create and destroy the window,
+respectively.