Index: CKEditor/trunk/_source/core/plugindefinition.js
===================================================================
--- CKEditor/trunk/_source/core/plugindefinition.js	(revision 6813)
+++ CKEditor/trunk/_source/core/plugindefinition.js	(revision 6814)
@@ -28,4 +28,21 @@
  * {
  *     requires : [ 'button', 'selection' ]
+ * });
+ */
+
+/**
+ * A list of language files available for this plugin. These files are stored inside 
+ * the "lang" directory, which is inside the plugin directory, follow the name 
+ * pattern of "langCode.js", and contain a language definition created with {@link CKEDITOR.pluginDefinition#setLang}.
+ * While the plugin is being loaded, the editor checks this list to see if
+ * a language file of the current editor language ({@link CKEDITOR.editor#langCode}) 
+ * is available, and if so, loads it. Otherwise, the file represented by the first list item
+ * in the list is loaded.
+ * @name CKEDITOR.pluginDefinition.prototype.lang
+ * @type Array
+ * @example
+ * CKEDITOR.plugins.add( 'sample',
+ * {
+ *     lang : [ 'en', 'fr' ]
  * });
  */
Index: CKEditor/trunk/_source/core/plugins.js
===================================================================
--- CKEditor/trunk/_source/core/plugins.js	(revision 6813)
+++ CKEditor/trunk/_source/core/plugins.js	(revision 6814)
@@ -77,4 +77,18 @@
 	});
 
+/**
+ * Loads a specific language file, or auto detect it. A callback is
+ * then called when the file gets loaded.
+ * @param {String} pluginName The name of the plugin to which the provided translation
+ * 		should be attached.
+ * @param {String} languageCode The code of the language translation provided.
+ * @param {Object} languageEntries An object that contains pairs of label and
+ *		the respective translation.
+ * @example
+ * CKEDITOR.plugins.setLang( 'myPlugin', 'en', {
+ * 	title : 'My plugin',
+ * 	selectOption : 'Please select an option'
+ * } );
+ */
 CKEDITOR.plugins.setLang = function( pluginName, languageCode, languageEntries )
 {
Index: CKEditor/trunk/_source/plugins/button/plugin.js
===================================================================
--- CKEditor/trunk/_source/plugins/button/plugin.js	(revision 6813)
+++ CKEditor/trunk/_source/plugins/button/plugin.js	(revision 6814)
@@ -276,6 +276,6 @@
 /**
  * Adds a button definition to the UI elements list.
- * @param {String} The button name.
- * @param {Object} The button definition.
+ * @param {String} name The button name.
+ * @param {Object} definition The button definition.
  * @example
  * editorInstance.ui.addButton( 'MyBold',