Index: src/wp-includes/comment-template.php
===================================================================
--- src/wp-includes/comment-template.php	(revision 43298)
+++ src/wp-includes/comment-template.php	(working copy)
@@ -2194,9 +2194,10 @@
  *     @type array $fields {
  *         Default comment fields, filterable by default via the {@see 'comment_form_default_fields'} hook.
  *
- *         @type string $author Comment author field HTML.
- *         @type string $email  Comment author email field HTML.
- *         @type string $url    Comment author URL field HTML.
+ *         @type string $author  Comment author field HTML.
+ *         @type string $email   Comment author email field HTML.
+ *         @type string $url     Comment author URL field HTML.
+ *         @type string $cookies Comment cookie opt-in field HTML.
  *     }
  *     @type string $comment_field        The comment textarea field HTML.
  *     @type string $must_log_in          HTML element for a 'must be logged in to comment' message.