diff --git a/core/lib/Drupal/Core/Entity/ContentEntityForm.php b/core/lib/Drupal/Core/Entity/ContentEntityForm.php
index a667790..c0882a2 100644
--- a/core/lib/Drupal/Core/Entity/ContentEntityForm.php
+++ b/core/lib/Drupal/Core/Entity/ContentEntityForm.php
@@ -52,7 +52,8 @@ public function form(array $form, FormStateInterface $form_state) {
     $form = parent::form($form, $form_state);
 
     // Content entity forms only need to rebuild the entity in the validation
-    // and the submit handler.
+    // and the submit handler because Field API uses its own #after_build
+    // callback for its widgets.
     unset($form['#after_build']);
 
     $this->getFormDisplay($form_state)->buildForm($this->entity, $form, $form_state);
diff --git a/core/lib/Drupal/Core/Entity/EntityForm.php b/core/lib/Drupal/Core/Entity/EntityForm.php
index c126fad..d5b2c7a 100644
--- a/core/lib/Drupal/Core/Entity/EntityForm.php
+++ b/core/lib/Drupal/Core/Entity/EntityForm.php
@@ -135,7 +135,7 @@ protected function init(FormStateInterface $form_state) {
    * @see \Drupal\Core\Entity\EntityForm::afterBuild()
    */
   public function form(array $form, FormStateInterface $form_state) {
-    // Add process and after_build callbacks.
+    // Add #process and #after_build callbacks.
     $form['#process'][] = '::processForm';
     $form['#after_build'][] = '::afterBuild';
 
diff --git a/core/modules/config/src/Tests/ConfigEntityTest.php b/core/modules/config/src/Tests/ConfigEntityTest.php
index 1de0264..ac93e87 100644
--- a/core/modules/config/src/Tests/ConfigEntityTest.php
+++ b/core/modules/config/src/Tests/ConfigEntityTest.php
@@ -328,18 +328,18 @@ function testCRUDUI() {
     $this->assertNoFieldByName('size_value');
 
     $id = strtolower($this->randomMachineName());
-    $edit = array(
+    $edit = [
       'id' => $id,
       'label' => $this->randomString(),
       'size' => 'custom',
-    );
+    ];
     $this->drupalPostAjaxForm(NULL, $edit, 'size');
 
     // Check that the dependent element is shown after selecting a 'size' value.
     $this->assertFieldByName('size');
     $this->assertFieldByName('size_value');
 
-    // Test the same scenario but it in a non-js case by using a js-hidden
+    // Test the same scenario but it in a non-JS case by using a 'js-hidden'
     // submit button.
     $this->drupalGet('admin/structure/config_test/add');
     $this->assertFieldByName('size');
@@ -351,7 +351,7 @@ function testCRUDUI() {
 
     // Submit the form with the regular 'Save' button and check that the entity
     // values are correct.
-    $edit += array('size_value' => 'medium');
+    $edit += ['size_value' => 'medium'];
     $this->drupalPostForm(NULL, $edit, 'Save');
 
     $entity = entity_load('config_test', $id);
diff --git a/core/modules/config/tests/config_test/src/ConfigTestForm.php b/core/modules/config/tests/config_test/src/ConfigTestForm.php
index 975e27b..56195e2 100644
--- a/core/modules/config/tests/config_test/src/ConfigTestForm.php
+++ b/core/modules/config/tests/config_test/src/ConfigTestForm.php
@@ -119,7 +119,7 @@ public static function updateSize(array $form, FormStateInterface $form_state) {
   }
 
   /**
-   * Element submit handler for non-js testing.
+   * Element submit handler for non-JS testing.
    */
   public static function changeSize(array $form, FormStateInterface $form_state) {
     $form_state->setRebuild();