Index: /CKEditor/trunk/CHANGES.html
===================================================================
--- /CKEditor/trunk/CHANGES.html	(revision 5410)
+++ /CKEditor/trunk/CHANGES.html	(revision 5411)
@@ -64,5 +64,6 @@
 		<li><a href="http://dev.fckeditor.net/ticket/5216">#5216</a> : Extend CKEDITOR.appendTo to allow a data parameter for the initial value.</li>
 		<li><a href="http://dev.fckeditor.net/ticket/5024">#5024</a> : Added sample to show how to output XHTML and avoid deprecated tags.</li>
-		<li><a href="http://dev.fckeditor.net/ticket/4358">#4358</a> : Update list properties dialog box was missed.</li>
+		<li><a href="http://dev.fckeditor.net/ticket/4358">#4358</a> : Aligning <b>List Properties</b> dialog with FCKEditor 2.x.</li>
+		<li><a href="http://dev.fckeditor.net/ticket/5485">#5485</a> : Adding the <b>contentsLanguage</b> configuration option.</li>
 	</ul>
 	<p>
Index: /CKEditor/trunk/_source/core/config.js
===================================================================
--- /CKEditor/trunk/_source/core/config.js	(revision 5410)
+++ /CKEditor/trunk/_source/core/config.js	(revision 5411)
@@ -85,4 +85,14 @@
 	 */
 	contentsLangDirection : 'ltr',
+
+	/**
+	 * Language code of  the writting language which is used to author the editor
+	 * contents.
+	 * @default Same value with editor's UI language.
+	 * @type String
+	 * @example
+	 * config.contentsLanguage = 'fr';
+	 */
+	contentsLanguage : '',
 
 	/**
Index: /CKEditor/trunk/_source/plugins/wysiwygarea/plugin.js
===================================================================
--- /CKEditor/trunk/_source/plugins/wysiwygarea/plugin.js	(revision 5410)
+++ /CKEditor/trunk/_source/plugins/wysiwygarea/plugin.js	(revision 5411)
@@ -1,3 +1,3 @@
-﻿/*
+/*
 Copyright (c) 2003-2010, CKSource - Frederico Knabben. All rights reserved.
 For licensing, see LICENSE.html or http://ckeditor.com/license
@@ -656,5 +656,6 @@
 									data =
 										config.docType +
-										'<html dir="' + config.contentsLangDirection + '">' +
+										'<html dir="' + config.contentsLangDirection + '"' +
+											' lang="' + ( config.contentsLanguage || editor.langCode ) + '">' +
 										'<title>' + frameLabel + '</title>' +
 										'<head>' +
