diff --git a/API.txt b/API.txt
index 36d85d1..c4b557f 100644
--- a/API.txt
+++ b/API.txt
@@ -982,6 +982,12 @@ hooks in the plugins bundled with Flot.
    order wrong. The hook only gets one event, though (either for the
    overlay or for the static canvas).
 
+   Note that custom plot events generated by Flot are not generated on
+   eventHolder, but on the div placeholder supplied as the first
+   argument to the plot call. You can get that with
+   plot.getPlaceholder() - that's probably also the one you should use
+   if you need to fire a custom event.
+
 
  - drawOverlay  [phase 7]