diff -u b/core/misc/message.js b/core/misc/message.js
--- b/core/misc/message.js
+++ b/core/misc/message.js
@@ -7,6 +7,11 @@
   'use strict';
 
   var defaultMessageWrapperSelector = '[data-drupal-messages]';
+  var messagesTypes = {
+    status: Drupal.t('Status message'),
+    error: Drupal.t('Error message'),
+    warning: Drupal.t('Warning message')
+  };
 
   /**
    * @typedef {object} Drupal.message~messageDefinition
@@ -50,6 +55,15 @@
      *   Message type, can be either 'status', 'error' or 'warning'.
      * @param {object} [options]
      *   The context of the message, used for removing messages again.
+     * @param {string} [options.index]
+     *   The message index, it can be a simple value: `'filevalidationerror'`
+     *   or several values separated by a space: `'mymodule formvalidation'`
+     *   which can be used as a sort of tag for message deletion.
+     * @param {string} [options.announce]
+     *   Screen-reader version of the message if necessary. To prevent a message
+     *   being sent to Drupal.announce() this should be `''`.
+     * @param {string} [options.priority]
+     *   Priority of the message for Drupal.announce().
      *
      * @return {string}
      *   Index of message.
@@ -64,47 +78,87 @@
       announce(message, type, options);
       // Use the provided index for the message or generate a unique key to
       // allow message deletion.
-      options.index = options.index || Math.random().toFixed(15).replace('0.', '');
-      messageWrapper.innerHTML += Drupal.theme('message', {text: message, type: type}, options);
+      options.index = type + ' ' + (options.index || Math.random().toFixed(15).replace('0.', ''));
+      messageWrapper.appendChild(Drupal.theme('message', {text: message, type: type}, options));
 
       return options.index;
     }
 
     /**
-     * Removes messages from the message area.
+     * Select a set of messages based on type or index.
      *
-     * @name Drupal.message~messageDefinition.remove
+     * @name Drupal.message~messageDefinition.select
      *
      * @param {string|Array.<string>} index
-     *   Index of the message to remove, as returned by
-     *   {@link Drupal.message~messageDefinition.add}, or an
-     *   array of indexes.
+     *   The message index or type to delete from the area.
      *
-     * @return {number}
-     *  Number of removed messages.
+     * @return {NodeList|Array}
+     *   Elements found.
      */
-    function messageRemove(index) {
-      // If there is no argument or if the argument is an empty array,
-      // no message can be removed.
+    function messageSelect(index) {
+      var selectors;
+
+      // When there are nothing to select, return an empty list.
       if (!index || (Array.isArray(index) && index.length === 0)) {
-        return 0;
+        return [];
       }
 
-      var removeSelectors = (Array.isArray(index) ? index : [index])
-        .map(function (messageIndex) {
-          return '[data-drupal-message="' + messageIndex + '"]';
-        });
+      var whitespace = /\s+/;
+      var indexes = Array.isArray(index) ? index : [index];
+      selectors = indexes.map(function (currentIndex) {
+        // If the index has spaces, add several data matches, the same way
+        // class names work.
+        return currentIndex.trim()
+          .split(whitespace)
+          .map(function (i) {
+            return '[data-drupal-message~="' + i + '"]';
+          })
+          .join('');
+      });
 
-      var toRemove = messageWrapper.querySelectorAll(removeSelectors.join(','));
-      var length = toRemove.length;
-      for (var i = 0; i < length; i++) {
-        messageWrapper.removeChild(toRemove[i]);
+      return messageWrapper.querySelectorAll(selectors.join(','));
+    }
+
+    /**
+     * Helper to remove elements.
+     *
+     * @param {NodeList|Array.<HTMLElement>} elements
+     *   DOM Nodes to be removed.
+     *
+     * @return {number}
+     *  Number of removed nodes.
+     */
+    function removeElements(elements) {
+      if (!elements || !elements.length) {
+        return 0;
       }
 
+      var length = elements.length;
+      for (var i = 0; i < length; i++) {
+        messageWrapper.removeChild(elements[i]);
+      }
       return length;
     }
 
     /**
+     * Removes messages from the message area.
+     *
+     * @name Drupal.message~messageDefinition.remove
+     *
+     * @param {string|Array.<string>} index
+     *   Index of the message to remove, as returned by
+     *   {@link Drupal.message~messageDefinition.add}, or an
+     *   array of indexes.
+     *
+     * @return {number}
+     *  Number of removed messages.
+     */
+    function messageRemove(options) {
+      var messages = messageSelect(options);
+      return removeElements(messages);
+    }
+
+    /**
      * Removes all messages from the message area.
      *
      * @name Drupal.message~messageDefinition.clear
@@ -116,22 +170,13 @@
      *  Number of removed messages.
      */
     function messageClear(type) {
-      var messageSelector = '[data-drupal-message]';
-      if (type) {
-        messageSelector += '[class~="messages--' + type + '"]';
-      }
-
-      var toRemove = messageWrapper.querySelectorAll(messageSelector);
-      var length = toRemove.length;
-      for (var i = 0; i < length; i++) {
-        messageWrapper.removeChild(toRemove[i]);
-      }
-
-      return length;
+      var messages = messageWrapper.querySelectorAll('[data-drupal-message]');
+      return removeElements(messages);
     }
 
     return {
       add: messageAdd,
+      select: messageSelect,
       remove: messageRemove,
       clear: messageClear
     };
@@ -156,13 +201,11 @@
     if (!options.priority && (type === 'warning' || type === 'error')) {
       options.priority = 'assertive';
     }
-
     // If screen reader message is not disabled announce screen reader specific
     // text or fallback to the displayed message.
-    Drupal.announce((typeof options.announce === 'string' && options.announce !== '') ?
-      options.announce :
-      message, options.priority);
-
+    if (options.announce !== '') {
+      Drupal.announce(options.announce || message, options.priority);
+    }
   }
 
   /**
@@ -174,17 +217,37 @@
    *   The message text.
    * @param {string} message.type
    *   The message type.
-   * @param {object} [options]
+   * @param {object} options
    *   The message context.
    * @param {string} options.index
    *   Index of the message, for reference.
    *
-   * @return {string}
-   *   A string representing a DOM fragment.
+   * @return {HTMLElement}
+   *   A DOM Node.
    */
   Drupal.theme.message = function (message, options) {
-    return '<div class="messages messages--' + message.type + '" ' +
-      'data-drupal-message="' + options.index + '"> ' + message.text + '</div>';
+    var messageText = message.text;
+    var messageWraper = document.createElement('div');
+    messageWraper.setAttribute('class', 'messages messages--' + message.type);
+    messageWraper.setAttribute('role', 'contentinfo');
+    messageWraper.setAttribute('data-drupal-message', options.index);
+    if (message.type in messagesTypes) {
+      messageWraper.setAttribute('aria-label', messagesTypes[message.type]);
+      messageText = '<h2 class="visually-hidden">' + messagesTypes[message.type] + '</h2>\n' + message.text;
+    }
+
+    // Alerts have a different HTML structure
+    if (message.type === 'error') {
+      var ariaAlert = document.createElement('div');
+      ariaAlert.setAttribute('role', 'alert');
+      ariaAlert.innerHTML = messageText;
+      messageWraper.appendChild(ariaAlert);
+    }
+    else {
+      messageWraper.innerHTML = messageText;
+    }
+
+    return messageWraper;
   };
 
 }(Drupal));
diff -u b/core/modules/system/tests/modules/js_message_test/js/js_message_test.js b/core/modules/system/tests/modules/js_message_test/js/js_message_test.js
--- b/core/modules/system/tests/modules/js_message_test/js/js_message_test.js
+++ b/core/modules/system/tests/modules/js_message_test/js/js_message_test.js
@@ -68,8 +68,8 @@
         defaultMessageArea.add('Msg-' + total, 'status');
       });
 
-      $('[data-action="clear-type"]').once('clear-type').on('click', function (e) {
-        defaultMessageArea.clear('error');
+      $('[data-action="remove-type"]').once('remove-type').on('click', function (e) {
+        defaultMessageArea.remove('error');
       });
 
       $('[data-action="clear-all"]').once('clear-all').on('click', function (e) {
diff -u b/core/modules/system/tests/modules/js_message_test/src/Controller/JSMessageTestController.php b/core/modules/system/tests/modules/js_message_test/src/Controller/JSMessageTestController.php
--- b/core/modules/system/tests/modules/js_message_test/src/Controller/JSMessageTestController.php
+++ b/core/modules/system/tests/modules/js_message_test/src/Controller/JSMessageTestController.php
@@ -89,14 +89,14 @@
         'data-action' => 'add-multiple-error',
       ],
     ];
-    $buttons['clear-type'] = [
+    $buttons['remove-type'] = [
       '#type' => 'html_tag',
       '#tag' => 'button',
-      '#value' => "Clear 'error' type",
+      '#value' => "Remove 'error' type",
       '#attributes' => [
         'type' => 'button',
-        'id' => 'clear-type',
-        'data-action' => 'clear-type',
+        'id' => 'remove-type',
+        'data-action' => 'remove-type',
       ],
     ];
     $buttons['clear-all'] = [
diff -u b/core/tests/Drupal/FunctionalJavascriptTests/Core/JsMessageTest.php b/core/tests/Drupal/FunctionalJavascriptTests/Core/JsMessageTest.php
--- b/core/tests/Drupal/FunctionalJavascriptTests/Core/JsMessageTest.php
+++ b/core/tests/Drupal/FunctionalJavascriptTests/Core/JsMessageTest.php
@@ -76,7 +76,7 @@
     $current_messages[] = $last_message;
     $this->click('[id="add-multiple-error"]');
     $this->assertCurrentMessages($current_messages);
-    $this->click('[id="clear-type"]');
+    $this->click('[id="remove-type"]');
     $this->assertCurrentMessages([$last_message]);
     $this->click('[id="clear-all"]');
     $this->assertCurrentMessages([]);