diff --git a/core/modules/comment/comment.module b/core/modules/comment/comment.module
index 909f543..c853e3a 100644
--- a/core/modules/comment/comment.module
+++ b/core/modules/comment/comment.module
@@ -1132,7 +1132,6 @@ function comment_form_node_type_form_alter(&$form, $form_state) {
  * comment_form_node_type_form_alter().
  *
  * @see comment_form_node_type_form_alter()
- * @see node_type_form()
  */
 function comment_translation_configuration_element_submit($form, &$form_state) {
   // The comment translation settings form element is embedded into the node
diff --git a/core/modules/system/tests/modules/entity_test/entity_test.module b/core/modules/system/tests/modules/entity_test/entity_test.module
index b5a4f94..7844dcb 100644
--- a/core/modules/system/tests/modules/entity_test/entity_test.module
+++ b/core/modules/system/tests/modules/entity_test/entity_test.module
@@ -62,6 +62,11 @@ function entity_test_menu() {
 
 /**
  * Menu callback: displays the 'Add new entity_test' form.
+ *
+ * @return array
+ *   The processed form for a new entity_test.
+ *
+ * @see entity_test_menu()
  */
 function entity_test_add() {
   drupal_set_title(t('Create an entity_test'));
@@ -71,6 +76,14 @@ function entity_test_add() {
 
 /**
  * Menu callback: displays the 'Edit existing entity_test' form.
+ *
+ * @param array $entity
+ *   The entity to be edited.
+ *
+ * @return array
+ *   The processed form for the edited entity_test.
+ *
+ * @see entity_test_menu()
  */
 function entity_test_edit(EntityTest $entity) {
   drupal_set_title($entity->label(), PASS_THROUGH);
diff --git a/core/modules/taxonomy/lib/Drupal/taxonomy/TermTranslationController.php b/core/modules/taxonomy/lib/Drupal/taxonomy/TermTranslationController.php
index a8e6dd7..2fa4227 100644
--- a/core/modules/taxonomy/lib/Drupal/taxonomy/TermTranslationController.php
+++ b/core/modules/taxonomy/lib/Drupal/taxonomy/TermTranslationController.php
@@ -24,7 +24,11 @@ public function entityFormAlter(array &$form, array &$form_state, EntityInterfac
   }
 
   /**
-   * Submit handler for the save action.
+   * Form submission handler for TermTranslationController::entityFormAlter().
+   *
+   * This handles the save action.
+   *
+   * @see \Drupal\Core\Entity\EntityFormController::build().
    */
   function entityFormSave(array $form, array &$form_state) {
     if ($this->getSourceLangcode($form_state)) {
diff --git a/core/modules/translation_entity/lib/Drupal/translation_entity/EntityTranslationController.php b/core/modules/translation_entity/lib/Drupal/translation_entity/EntityTranslationController.php
index ddf6589..6966d0b 100644
--- a/core/modules/translation_entity/lib/Drupal/translation_entity/EntityTranslationController.php
+++ b/core/modules/translation_entity/lib/Drupal/translation_entity/EntityTranslationController.php
@@ -247,7 +247,15 @@ public function entityFormAlter(array &$form, array &$form_state, EntityInterfac
   }
 
   /**
-   * Process callback that handles entity form shared elements.
+   * Process callback: Determines which elements get clue in the form.
+   *
+   * @param array $element
+   *   Form API element.
+   *
+   * @return array
+   *   A processed element with the shared elements marked with a clue.
+   *
+   * @see \Drupal\translation_entity\EntityTranslationController::entityFormAlter()
    */
   public function entityFormSharedElements($element) {
     static $ignored_types;
@@ -317,8 +325,15 @@ protected function addTranslatabilityClue(&$element) {
 
   /**
    * Entity builder method.
+   *
+   * @param string $entity_type
+   *   The type of the entity.
+   * @param \Drupal\Core\Entity\EntityInterface $entity
+   *   The entity whose form is being built.
+   *
+   * @see \Drupal\translation_entity\EntityTranslationController::entityFormAlter()
    */
-  public function entityFormEntityBuild($entity_type, $entity, $form, &$form_state) {
+  public function entityFormEntityBuild($entity_type, EntityInterface $entity, array $form, array &$form_state) {
     $form_controller = translation_entity_form_controller($form_state);
     $form_langcode = $form_controller->getFormLangcode($form_state);
     $source_langcode = $this->getSourceLangcode($form_state);
@@ -340,7 +355,9 @@ public function entityFormEntityBuild($entity_type, $entity, $form, &$form_state
   }
 
   /**
-   * Submit handler for the source language change.
+   * Form submission handler for EntityTranslationController::entityFormAlter().
+   *
+   * Takes care of the source language change.
    */
   public function entityFormSourceChange($form, &$form_state) {
     $form_controller = translation_entity_form_controller($form_state);
@@ -353,7 +370,9 @@ public function entityFormSourceChange($form, &$form_state) {
   }
 
   /**
-   * Submit handler for the entity deletion.
+   * Form submission handler for EntityTranslationController::entityFormAlter().
+   *
+   * Takes care of entity deletion.
    */
   function entityFormDelete($form, &$form_state) {
     $form_controller = translation_entity_form_controller($form_state);
@@ -364,7 +383,9 @@ function entityFormDelete($form, &$form_state) {
   }
 
   /**
-   * Submit handler for the entity translation deletion.
+   * Form submission handler for EntityTranslationController::entityFormAlter().
+   *
+   * Takes care of entity translation deletion.
    */
   function entityFormDeleteTranslation($form, &$form_state) {
     $form_controller = translation_entity_form_controller($form_state);
@@ -377,7 +398,7 @@ function entityFormDeleteTranslation($form, &$form_state) {
   /**
    * Returns the title to be used for the entity form page.
    *
-   * @param Drupal\Core\Entity\EntityInterface $entity
+   * @param \Drupal\Core\Entity\EntityInterface $entity
    *   The entity whose form is being altered.
    */
   protected function entityFormTitle(EntityInterface $entity) {
diff --git a/core/modules/translation_entity/translation_entity.admin.inc b/core/modules/translation_entity/translation_entity.admin.inc
index 34e3b37..e9f87e8 100644
--- a/core/modules/translation_entity/translation_entity.admin.inc
+++ b/core/modules/translation_entity/translation_entity.admin.inc
@@ -5,8 +5,10 @@
  * The entity translation administration forms.
  */
 
+use Drupal\Core\Entity\EntityInterface;
+
 /**
- * Returns the confirmation form for changing field translatability.
+ * Form constructor for the confirmation of translatability switching.
  */
 function translation_entity_translatable_form(array $form, array &$form_state, $field_name) {
   $field = field_info_field($field_name);
@@ -35,7 +37,7 @@ function translation_entity_translatable_form(array $form, array &$form_state, $
 }
 
 /**
- * Submit handler for the field settings form.
+ * Form submission handler for translation_entity_translatable_form().
  *
  * This submit handler maintains consistency between the translatability of an
  * entity and the language under which the field data is stored. When a field is
@@ -86,10 +88,16 @@ function translation_entity_translatable_form_submit(array $form, array $form_st
   batch_set($batch);
 }
 
-/*
+/**
  * Toggles translatability of the given field.
  *
  * This is called from a batch operation, but should only run once per field.
+ *
+ * @param bool $translatable
+ *   Indicator of whether the field should be made translatable (TRUE) or
+ *   untranslatble (FALSE).
+ * @param string $field_name
+ *   Field machine name.
  */
 function translation_entity_translatable_switch($translatable, $field_name) {
   $field = field_info_field($field_name);
@@ -103,7 +111,13 @@ function translation_entity_translatable_switch($translatable, $field_name) {
 }
 
 /**
- * Converts field data to or from LANGUAGE_NOT_SPECIFIED.
+ * Batch callback: Converts field data to or from LANGUAGE_NOT_SPECIFIED.
+ *
+ * @param bool $translatable
+ *   Indicator of whether the field should be made translatable (TRUE) or
+ *   untranslatble (FALSE).
+ * @param string $field_name
+ *   Field machine name.
  */
 function translation_entity_translatable_batch($translatable, $field_name, &$context) {
   $entity_types = array();
@@ -218,7 +232,7 @@ function translation_entity_translatable_batch($translatable, $field_name, &$con
 /**
  * Stores the given field translations.
  */
-function _translation_entity_update_field($entity_type, $entity, $field_name) {
+function _translation_entity_update_field($entity_type, EntityInterface $entity, $field_name) {
   $empty = 0;
   $field = field_info_field($field_name);
 
@@ -238,7 +252,7 @@ function _translation_entity_update_field($entity_type, $entity, $field_name) {
 }
 
 /**
- * Checks the exit status of the batch operation.
+ * Batch finished callback: Checks the exit status of the batch operation.
  */
 function translation_entity_translatable_batch_done($success, $results, $operations) {
   if ($success) {
diff --git a/core/modules/translation_entity/translation_entity.module b/core/modules/translation_entity/translation_entity.module
index a6dc4ce..547903a 100644
--- a/core/modules/translation_entity/translation_entity.module
+++ b/core/modules/translation_entity/translation_entity.module
@@ -634,9 +634,15 @@ function translation_entity_enable_widget($entity_type, $bundle, array &$form, a
 }
 
 /**
- * Process handler for the language_configuration form element.
+ * Process callback: Expands the language_configuration form element.
+ *
+ * @param array $element
+ *   Form API element.
+ *
+ * @return
+ *   Processed language configuration element.
  */
-function translation_entity_language_configuration_element_process($element, array &$form_state, array &$form) {
+function translation_entity_language_configuration_element_process(array $element, array &$form_state, array &$form) {
   $form_state['translation_entity']['key'] = $element['#name'];
   $context = $form_state['language'][$element['#name']];
 
@@ -654,11 +660,13 @@ function translation_entity_language_configuration_element_process($element, arr
 }
 
 /**
- * Configuration element validation handler.
+ * Form validation handler for element added with translation_entity_language_configuration_element_process().
  *
  * Checks whether translation can be enabled: if language is set to one of the
  * special languages and language selector is not hidden, translation cannot be
  * enabled.
+ *
+ * @see translation_entity_language_configuration_element_submit()
  */
 function translation_entity_language_configuration_element_validate($element, array &$form_state, array $form) {
   $key = $form_state['translation_entity']['key'];
@@ -675,9 +683,11 @@ function translation_entity_language_configuration_element_validate($element, ar
 }
 
 /**
- * Configuration form submit handler.
+ * Form submission handler for element added with translation_entity_language_configuration_element_process().
  *
  * Stores the entity translation settings.
+ *
+ * @see translation_entity_language_configuration_element_validate()
  */
 function translation_entity_language_configuration_element_submit(array $form, array &$form_state) {
   $key = $form_state['translation_entity']['key'];
diff --git a/core/modules/translation_entity/translation_entity.pages.inc b/core/modules/translation_entity/translation_entity.pages.inc
index 4d92f52..b7b9a8c 100644
--- a/core/modules/translation_entity/translation_entity.pages.inc
+++ b/core/modules/translation_entity/translation_entity.pages.inc
@@ -236,7 +236,7 @@ function translation_entity_prepare_translation(EntityInterface $entity, Languag
 }
 
 /**
- * Form builder for the translation deletion confirmation.
+ * Form constructor for the translation deletion confirmation.
  */
 function translation_entity_delete_confirm(array $form, array $form_state, EntityInterface $entity, Language $language) {
   $langcode = $language->langcode;
@@ -253,7 +253,7 @@ function translation_entity_delete_confirm(array $form, array $form_state, Entit
 }
 
 /**
- * Submit handler for the translation deletion confirmation.
+ * Form submission handler for translation_entity_delete_confirm().
  */
 function translation_entity_delete_confirm_submit(array $form, array &$form_state) {
   list($entity, $language) = $form_state['build_info']['args'];
diff --git a/core/modules/user/lib/Drupal/user/ProfileTranslationController.php b/core/modules/user/lib/Drupal/user/ProfileTranslationController.php
index e7dcd65..91e129b 100644
--- a/core/modules/user/lib/Drupal/user/ProfileTranslationController.php
+++ b/core/modules/user/lib/Drupal/user/ProfileTranslationController.php
@@ -24,7 +24,11 @@ public function entityFormAlter(array &$form, array &$form_state, EntityInterfac
   }
 
   /**
-   * Submit handler for the save action.
+   * Form submission handler for ProfileTranslationController::entityFormAlter().
+   *
+   * This handles the save action.
+   *
+   * @see \Drupal\Core\Entity\EntityFormController::build().
    */
   function entityFormSave(array $form, array &$form_state) {
     if ($this->getSourceLangcode($form_state)) {