diff --git a/IPython/html/static/custom/custom.js b/IPython/html/static/custom/custom.js
index b618cd3..2f28784 100644
--- a/IPython/html/static/custom/custom.js
+++ b/IPython/html/static/custom/custom.js
@@ -11,6 +11,16 @@
* It will be executed by the ipython notebook at load time.
*
* Same thing with `profile/static/custom/custom.css` to inject custom css into the notebook.
+ *
+ * Classes and functions are available at load time and may be accessed plainly:
+ *
+ * IPython.Cell.options_default.cm_config.extraKeys = {Home: "goLineLeft", End: "goLineRight"};
+ *
+ * Instances are created later however and must be accessed using events:
+ *
+ * $([IPython.events]).on("app_initialized.NotebookApp", function () {
+ * IPython.keyboard_manager....
+ * });
*
* __Example 1:__
*