diff --git wp-includes/widgets.php wp-includes/widgets.php
index f3ca44a..45bb43e 100644
--- wp-includes/widgets.php
+++ wp-includes/widgets.php
@@ -122,8 +122,11 @@ class WP_Widget {
 		return 'widget-' . $this->id_base . '-' . $this->number . '-' . $field_name;
 	}
 
-	// Private Functions. Don't worry about these.
-
+	/**
+	 * Register all widget instances of this widget class.
+	 *
+	 * @access private
+	 */
 	public function _register() {
 		$settings = $this->get_settings();
 		$empty = true;
@@ -146,6 +149,14 @@ class WP_Widget {
 		}
 	}
 
+	/**
+	 * Set the internal order number for the widget instance.
+	 *
+	 * @access private
+	 *
+	 * @param int $number The unique order number of this widget instance
+	 *                    compared to other instances of the same class.
+	 */
 	public function _set($number) {
 		$this->number = $number;
 		$this->id = $this->id_base . '-' . $number;
@@ -362,19 +373,37 @@ class WP_Widget {
 		return $return;
 	}
 
-	/** Helper function: Registers a single instance. */
+	/**
+	 * Register an instance of the widget class.
+	 *
+	 * @access private
+	 *
+	 * @param  integer $number The unique order number of this widget instance
+	 *                         compared to other instances of the same class.
+	 */
 	public function _register_one($number = -1) {
 		wp_register_sidebar_widget(	$this->id, $this->name,	$this->_get_display_callback(), $this->widget_options, array( 'number' => $number ) );
 		_register_widget_update_callback( $this->id_base, $this->_get_update_callback(), $this->control_options, array( 'number' => -1 ) );
 		_register_widget_form_callback(	$this->id, $this->name,	$this->_get_form_callback(), $this->control_options, array( 'number' => $number ) );
 	}
 
+	/**
+	 * Save the settings for all instances of the widget class.
+	 *
+	 * @param array $settings Multi-dimensional array of widget instance settings.
+	 */
 	public function save_settings($settings) {
 		$settings['_multiwidget'] = 1;
 		update_option( $this->option_name, $settings );
 	}
 
+	/**
+	 * Get the settings for all instances of the widget class.
+	 *
+	 * @return array Multi-dimensional array of widget instance settings.
+	 */
 	public function get_settings() {
+
 		$settings = get_option($this->option_name);
 
 		if ( false === $settings && isset($this->alt_option_name) )
@@ -407,10 +436,20 @@ class WP_Widget_Factory {
 		add_action( 'widgets_init', array( $this, '_register_widgets' ), 100 );
 	}
 
+	/**
+	 * Register a widget class.
+	 *
+	 * @param  mixed $widget_class A subclass of WP_Widget.
+	 */
 	public function register($widget_class) {
 		$this->widgets[$widget_class] = new $widget_class();
 	}
 
+	/**
+	 * Unregister a widget class.
+	 *
+	 * @param  mixed $widget_class A subclass of WP_Widget.
+	 */
 	public function unregister($widget_class) {
 		if ( isset($this->widgets[$widget_class]) )
 			unset($this->widgets[$widget_class]);
@@ -448,7 +487,7 @@ global $wp_registered_sidebars, $wp_registered_widgets, $wp_registered_widget_co
 $wp_registered_sidebars = array();
 
 /**
- * Stores the registered widgets.
+ * Stores instances of widgets.
  *
  * @global array $wp_registered_widgets
  * @since 2.2.0
@@ -683,7 +722,7 @@ function unregister_sidebar( $name ) {
 }
 
 /**
- * Register widget for use in sidebars.
+ * Register an instance of a widget.
  *
  * The default widget option is 'classname' that can be overridden.
  *
@@ -698,7 +737,12 @@ function unregister_sidebar( $name ) {
  * @param int|string $id Widget ID.
  * @param string $name Widget display title.
  * @param callback $output_callback Run when widget is called.
- * @param array|string $options Optional. Widget Options.
+ * @param array $options {
+ *     An array of supplementary widget options for the instance. Optional.
+ *
+ *     @type string $classname Classname for the widget's HTML container.
+ *                             Optional. Defaults to the output callback.
+ * }
  * @param mixed $params,... Widget parameters to add to widget.
  * @return null Will return if $output_callback is empty after removing widget.
  */
@@ -1202,7 +1246,7 @@ function is_active_sidebar( $index ) {
 /* Internal Functions */
 
 /**
- * Retrieve full list of sidebars and their widgets.
+ * Retrieve full list of sidebars and their widget instance IDs.
  *
  * Will upgrade sidebar widget list, if needed. Will also save updated list, if
  * needed.