Index: /CKEditor/trunk/_source/core/editor.js
===================================================================
--- /CKEditor/trunk/_source/core/editor.js	(revision 4326)
+++ /CKEditor/trunk/_source/core/editor.js	(revision 4327)
@@ -1,3 +1,3 @@
-/*
+/*
 Copyright (c) 2003-2009, CKSource - Frederico Knabben. All rights reserved.
 For licensing, see LICENSE.html or http://ckeditor.com/license
@@ -437,4 +437,11 @@
 		},
 
+		/**
+		 * Add a trunk of css text to the editor which will be applied to the wysiwyg editing document.
+		 * Note: This function should be called before editor is loaded to take effect.
+		 * @param css {String} CSS text.
+		 * @example
+		 * editorInstance.addCss( 'body { background-color: grey; }' ); 
+		 */
 		addCss : function( css )
 		{