diff -u b/core/misc/message.js b/core/misc/message.js
--- b/core/misc/message.js
+++ b/core/misc/message.js
@@ -16,10 +16,14 @@
    */
 
   /**
-   * woot
+   * Constructs a new instance of the Drupal.message object.
    *
-   * @param {HTMLElement?} messageWrapper
-   *   The zone where to add messages.
+   * This provides a uniform interface for adding and removing messages to a
+   * specific location on the page.
+   *
+   * @param {HTMLElement} messageWrapper
+   *   The zone where to add messages. If no element is supplied, the default
+   *   selector is used.
    *
    * @return {Drupal.message~messageDefinition}
    *   Object to add and remove messages.
@@ -31,12 +35,12 @@
     if (!messageWrapper) {
       messageWrapper = document.querySelector(defaultMessageWrapperSelector);
       if (!messageWrapper) {
-        throw new Error(Drupal.t('There is no @element on the page.', {'%element': defaultMessageWrapperSelector}));
+        throw new Error(Drupal.t('There is no @element on the page.', {'@element': defaultMessageWrapperSelector}));
       }
     }
 
     /**
-     * Displays a message on the page.
+     * Sequentially adds a message to the defined location in the page.
      *
      * @name Drupal.message~messageDefinition.add
      *
@@ -84,7 +88,7 @@
         throw new Error(Drupal.t('Object.message() expect a message to remove.'));
       }
 
-      var removeSelectors = (messages instanceof Array ? messages : [messages])
+      var removeSelectors = (Array.isArray(messages) ? messages : [messages])
         .map(function (messageIndex) {
           return '[data-drupal-message="' + messageIndex + '"]';
         });
@@ -99,7 +103,6 @@
     }
 
     return {
-      element: messageWrapper,
       add: messageAdd,
       remove: messageRemove
     };