diff --git a/src/wp-admin/includes/template.php b/src/wp-admin/includes/template.php
index c5122dd611..c10402a488 100644
--- a/src/wp-admin/includes/template.php
+++ b/src/wp-admin/includes/template.php
@@ -24,16 +24,51 @@ class Walker_Category_Checklist extends Walker {
 	var $tree_type = 'category';
 	var $db_fields = array ('parent' => 'parent', 'id' => 'term_id'); //TODO: decouple this
 
+	/**
+	 * Starts the list before the elements are added.
+	 *
+	 * @see Walker:start_lvl()
+	 *
+	 * @since 2.5.1
+	 *
+	 * @param string $output Passed by reference. Used to append additional content.
+	 * @param int    $depth  Depth of category. Used for tab indentation.
+	 * @param array  $args   An array of arguments. @see wp_terms_checklist()
+	 */
 	function start_lvl( &$output, $depth = 0, $args = array() ) {
 		$indent = str_repeat("\t", $depth);
 		$output .= "$indent<ul class='children'>\n";
 	}
 
+	/**
+	 * Ends the list of after the elements are added.
+	 *
+	 * @see Walker::end_lvl()
+	 *
+	 * @since 2.5.1
+	 *
+	 * @param string $output Passed by reference. Used to append additional content.
+	 * @param int    $depth  Depth of category. Used for tab indentation.
+	 * @param array  $args   An array of arguments. @see wp_terms_checklist()
+	 */
 	function end_lvl( &$output, $depth = 0, $args = array() ) {
 		$indent = str_repeat("\t", $depth);
 		$output .= "$indent</ul>\n";
 	}
 
+	/**
+	 * Start the element output.
+	 *
+	 * @see Walker::start_el()
+	 *
+	 * @since 2.5.1
+	 *
+	 * @param string $output   Passed by reference. Used to append additional content.
+	 * @param object $category The current term object.
+	 * @param int    $depth    Depth of the term in reference to parents. Default 0.
+	 * @param array  $args     An array of arguments. @see wp_terms_checklist()
+	 * @param int    $id       ID of the current term.
+	 */
 	function start_el( &$output, $category, $depth = 0, $args = array(), $id = 0 ) {
 		extract($args);
 		if ( empty($taxonomy) )
@@ -48,6 +83,18 @@ class Walker_Category_Checklist extends Walker {
 		$output .= "\n<li id='{$taxonomy}-{$category->term_id}'$class>" . '<label class="selectit"><input value="' . $category->term_id . '" type="checkbox" name="'.$name.'[]" id="in-'.$taxonomy.'-' . $category->term_id . '"' . checked( in_array( $category->term_id, $selected_cats ), true, false ) . disabled( empty( $args['disabled'] ), false, false ) . ' /> ' . esc_html( apply_filters('the_category', $category->name )) . '</label>';
 	}
 
+	/**
+	 * Ends the element output, if needed.
+	 *
+	 * @see Walker::end_el()
+	 *
+	 * @since 2.5.1
+	 *
+	 * @param string $output   Passed by reference. Used to append additional content.
+	 * @param object $category The current term object.
+	 * @param int    $depth    Depth of the term in reference to parents. Default 0.
+	 * @param array  $args     An array of arguments. @see wp_terms_checklist()
+	 */
 	function end_el( &$output, $category, $depth = 0, $args = array() ) {
 		$output .= "</li>\n";
 	}