diff --git a/includes/install.core.inc b/includes/install.core.inc
index 09f3cc50b403733bd4f9f9044826e804484e6eb4..273acd95a06fbac9e91b2c33910a8f383aad5ac9 100644
--- a/includes/install.core.inc
+++ b/includes/install.core.inc
@@ -847,6 +847,7 @@ function install_verify_pdo() {
  *
  * @see install_settings_form_validate()
  * @see install_settings_form_submit()
+ * @ingroup forms
  */
 function install_settings_form($form, &$form_state, &$install_state) {
   global $databases;
@@ -1070,6 +1071,8 @@ function _install_select_profile($profiles) {
  *   Array of metadata about state of form processing.
  * @param $profile_files
  *   Array of .profile files, as returned from file_scan_directory().
+ *
+ * @ingroup forms
  */
 function install_select_profile_form($form, &$form_state, $profile_files) {
   $profiles = array();
@@ -1246,7 +1249,9 @@ function install_select_locale(&$install_state) {
 }
 
 /**
- * Form API array definition for language selection.
+ * Form constructor for the language selection form.
+ *
+ * @ingroup forms
  */
 function install_select_locale_form($form, &$form_state, $locales, $profilename) {
   include_once DRUPAL_ROOT . '/includes/iso.inc';
@@ -1419,6 +1424,7 @@ function install_import_locales(&$install_state) {
  *
  * @see install_configure_form_validate()
  * @see install_configure_form_submit()
+ * @ingroup forms
  */
 function install_configure_form($form, &$form_state, &$install_state) {
   drupal_set_title(st('Configure site'));
@@ -1671,11 +1677,15 @@ function install_check_requirements($install_state) {
 }
 
 /**
- * Returns a Form API array definition for site configuration.
+ * Form constructor for a site configuration form.
+ *
+ * @param $install_state
+ *   An array of information about the current installation state.
  *
  * @see install_configure_form()
  * @see install_configure_form_validate()
  * @see install_configure_form_submit()
+ * @ingroup forms
  */
 function _install_configure_form($form, &$form_state, &$install_state) {
   include_once DRUPAL_ROOT . '/includes/locale.inc';
diff --git a/includes/mail.inc b/includes/mail.inc
index e3093729d6dee1308730ae159e82d07143417fd1..8479d8e9bfb22298a6c164a3ab6f4c3d933bd8c6 100644
--- a/includes/mail.inc
+++ b/includes/mail.inc
@@ -340,6 +340,9 @@ public function mail(array $message);
  * @param $indent (optional)
  *   A string to indent the text with. Only '>' characters are repeated on
  *   subsequent wrapped lines. Others are replaced by spaces.
+ *
+ * @return
+ *   The content of the email as a string with formatting applied.
  */
 function drupal_wrap_mail($text, $indent = '') {
   // Convert CRLF into LF.
diff --git a/includes/menu.inc b/includes/menu.inc
index ae83a41e34e0ce8437e89868963228e84804201a..0cb9d23b89c95c8e313560385e8d2b4859eb1eea 100644
--- a/includes/menu.inc
+++ b/includes/menu.inc
@@ -607,7 +607,7 @@ function _menu_load_objects(&$item, &$map) {
 }
 
 /**
- * Checks access to a menu item using the access callback
+ * Checks access to a menu item using the access callback.
  *
  * @param $item
  *   A menu router or menu link item
@@ -1592,7 +1592,7 @@ function _menu_tree_data(&$links, $parents, $depth) {
 }
 
 /**
- * Preprocesses the rendered tree for theme_menu_tree().
+ * Implements template_preprocess_HOOK() for theme_menu_tree().
  */
 function template_preprocess_menu_tree(&$variables) {
   $variables['tree'] = $variables['tree']['#children'];
@@ -2260,7 +2260,13 @@ function menu_local_tabs() {
 /**
  * Returns HTML for primary and secondary local tasks.
  *
+ * @param $variables
+ *   An associative array containing:
+ *     - primary: (optional) An array of local tasks (tabs).
+ *     - secondary: (optional) An array of local tasks (tabs).
+ *
  * @ingroup themeable
+ * @see menu_local_tasks()
  */
 function theme_menu_local_tasks(&$variables) {
   $output = '';