diff --git a/core/modules/node/node.module b/core/modules/node/node.module
index c19d2fa..2289fa4 100644
--- a/core/modules/node/node.module
+++ b/core/modules/node/node.module
@@ -1143,11 +1143,11 @@ function node_preprocess_block(&$variables) {
  *   - form: The complete node form.
  */
 function template_preprocess_node_edit_form(&$variables) {
-  foreach ($variables['form'] as $key => $value) {
-    // Prevent recursion loop by removing '#theme' and '#theme_wrappers' keys.
-    // See http://drupal.org/node/1920886.
-    if ($key == '#theme' || $key == '#theme_wrappers') {
-      unset($variables['form'][$key]);
+  // Prevent recursion loop by removing '#theme' and '#theme_wrappers' keys.
+  // See http://drupal.org/node/1920886.
+  foreach (array('#theme', '#theme_wrappers') as $theme_key) {
+    if (isset($variables['form'][$theme_key])) {
+      unset($variables['form'][$theme_key]);
     }
   }
 }
diff --git a/core/modules/node/templates/node-add-list.html.twig b/core/modules/node/templates/node-add-list.html.twig
index 5afc11d..60b732d 100644
--- a/core/modules/node/templates/node-add-list.html.twig
+++ b/core/modules/node/templates/node-add-list.html.twig
@@ -3,12 +3,12 @@
  * @file
  * Default theme implementation to list node types available for adding content.
  *
- * This list is displayed on the add content admin page.
+ * This list is displayed on the Add content admin page.
  *
  * Available variables:
- * - types: A list of content types.
- *   - type.add_link: Link to create a piece of content of this type.
- *   - type.description: Description of this type of content.
+ * - types: A list of content types, each with the following properties:
+ *   - add_link: Link to create a piece of content of this type.
+ *   - description: Description of this type of content.
  *
  * @see template_preprocess()
  * @see template_preprocess_node_add_list()
diff --git a/core/modules/node/templates/node-edit-form.html.twig b/core/modules/node/templates/node-edit-form.html.twig
index 842456b..dba7950 100644
--- a/core/modules/node/templates/node-edit-form.html.twig
+++ b/core/modules/node/templates/node-edit-form.html.twig
@@ -3,12 +3,15 @@
  * @file
  * Two column template for the node add/edit form.
  *
+ * This template will be used when a node edit form specifies 'node_edit_form'
+ * as its #theme callback.  Otherwise, by default, node add/edit forms will be
+ * themed by theme_form().
+ *
  * Available variables:
- * - form: Complete form. Use {{ form }} to print the entire form, or print a
- *   subset such as {{ form.actions }}. Use {% hide(form.actions) %} to
- *   temporarily suppress the printing of a given element.
- *   - form.advanced: The advanced options for the node form.
- *   - form.actions: The action buttons for save and delete.
+ * - form: The node add/edit form.
+ *
+ * @see seven_form_node_form_alter()
+ * @see template_preprocess_node_edit_form()
  *
  * @ingroup themable
  */
diff --git a/core/modules/node/templates/node.html.twig b/core/modules/node/templates/node.html.twig
index 1c0fcf7..15fe637 100644
--- a/core/modules/node/templates/node.html.twig
+++ b/core/modules/node/templates/node.html.twig
@@ -18,8 +18,9 @@
  * - display_submitted: Whether submission information should be displayed.
  * - submitted: Submission information created from name and date during
  *   template_preprocess_node().
- * - attributes: Remaining HTML attributes for the containing element.
- *   - attributes.class: Class information, containing:
+ * - attributes: HTML attributes for the containing element.
+ *   The attributes.class element may contain one or more of the following
+ *   classes:
  *     - node: The current template type (also known as a "theming hook").
  *     - node-[type]: The current node type. For example, if the node is a
  *       "Article" it would result in "node-article". Note that the machine
@@ -39,14 +40,14 @@
  *
  * Other variables:
  * - node: Full node entity.
- *   - node.type: Node type; for example, "page" or "article".
- *   - node.uid: User ID of the node author.
- *   - node.created: Formatted creation date.
- *   - node.promote: Flag for front page promotion state.
- *   - node.sticky: Flag for sticky post setting.
- *   - node.status: Flag for published status.
- *   - node.comment: State of comment settings for the node.
- *   - node.comment_count: Number of comments attached to the node.
+ *   - type: Node type; for example, "page" or "article".
+ *   - uid: User ID of the node author.
+ *   - created: Formatted creation date.
+ *   - promote: Flag for front page promotion state.
+ *   - sticky: Flag for sticky post setting.
+ *   - status: Flag for published status.
+ *   - comment: State of comment settings for the node.
+ *   - comment_count: Number of comments attached to the node.
  * - zebra: Outputs either "even" or "odd". Useful for zebra striping in
  *   teaser listings.
  * - id: Position of the node. Increments each time it's output.