1 files changed, 21 insertions, 8 deletions
diff --git a/lisp/subr.el b/lisp/subr.el
index d8618172103..7ddabbc0e90 100644
--- a/lisp/subr.el
+++ b/lisp/subr.el
@@ -854,24 +854,37 @@ in the current Emacs session, then this function may return nil."
 
 (defsubst event-start (event)
   "Return the starting position of EVENT.
-If EVENT is a mouse or key press or a mouse click, this returns the location
-of the event.
-If EVENT is a drag, this returns the drag's starting position.
-The return value is of the form
+EVENT should be a click, drag, or key press event.
+If it is a key press event, the return value has the form
+    (WINDOW POS (0 . 0) 0)
+If it is a click or drag event, it has the form
    (WINDOW AREA-OR-POS (X . Y) TIMESTAMP OBJECT POS (COL . ROW)
     IMAGE (DX . DY) (WIDTH . HEIGHT))
-The `posn-' functions access elements of such lists."
+The `posn-' functions access elements of such lists.
+For more information, see Info node `(elisp)Click Events'.
+
+If EVENT is a mouse or key press or a mouse click, this is the
+position of the event.  If EVENT is a drag, this is the starting
+position of the drag."
   (if (consp event) (nth 1 event)
     (list (selected-window) (point) '(0 . 0) 0)))
 
 (defsubst event-end (event)
   "Return the ending location of EVENT.
 EVENT should be a click, drag, or key press event.
-If EVENT is a click event, this function is the same as `event-start'.
-The return value is of the form
+If EVENT is a key press event, the return value has the form
+    (WINDOW POS (0 . 0) 0)
+If EVENT is a click event, this function is the same as
+`event-start'.  For click and drag events, the return value has
+the form
    (WINDOW AREA-OR-POS (X . Y) TIMESTAMP OBJECT POS (COL . ROW)
     IMAGE (DX . DY) (WIDTH . HEIGHT))
-The `posn-' functions access elements of such lists."
+The `posn-' functions access elements of such lists.
+For more information, see Info node `(elisp)Click Events'.
+
+If EVENT is a mouse or key press or a mouse click, this is the
+position of the event.  If EVENT is a drag, this is the starting
+position of the drag."
   (if (consp event) (nth (if (consp (nth 2 event)) 2 1) event)
     (list (selected-window) (point) '(0 . 0) 0)))