diff --git a/module/fid/src/Helper/FormLabel.php b/module/fid/src/Helper/FormLabel.php
index c6312fd11505a20b61985cc028d0f32fff2207d0..ea37df6067223e05d5130718cda4af904b83a247 100644
--- a/module/fid/src/Helper/FormLabel.php
+++ b/module/fid/src/Helper/FormLabel.php
@@ -1,7 +1,11 @@
 <?php
 /**
+ * Zend Form Label View Helper
+ *
  * Copyright (C) 2019 Leipzig University Library
  *
+ * PHP Version 7
+ *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation.
@@ -15,17 +19,38 @@
  * with this program; if not, write to the Free Software Foundation, Inc.,
  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  *
- * @author  Robert Lange <lange@ub.uni-leipzig.de>
- * @author  Sebastian Kehr <kehr@ub.uni-leipzig.de>
- * @license http://opensource.org/licenses/gpl-2.0.php GNU GPLv2
+ * @category VuFind
+ * @package  View_Helpers
+ * @author   Robert Lange <lange@ub.uni-leipzig.de>
+ * @author   Sebastian Kehr <kehr@ub.uni-leipzig.de>
+ * @license  http://opensource.org/licenses/gpl-2.0.php GNU GPLv2
+ * @link     https://vufind.org/wiki/development Wiki
  */
 namespace fid\Helper;
 
 use Zend\Form\Element;
+use Zend\Form\ElementInterface;
 use Zend\Form\View\Helper\FormLabel as Base;
 
+/**
+ * Improved Zend Form Label View Helper by adding attributes
+ *
+ * @category VuFind
+ * @package  View_Helpers
+ * @author   Robert Lange <lange@ub.uni-leipzig.de>
+ * @author   Sebastian Kehr <kehr@ub.uni-leipzig.de>
+ * @license  http://opensource.org/licenses/gpl-2.0.php GNU GPLv2
+ * @link     https://vufind.org/wiki/development Wiki
+ */
 class FormLabel extends Base
 {
+    /**
+     * {@inheritdoc}
+     *
+     * @param null|array|ElementInterface $element Form element
+     *
+     * @return string
+     */
     public function openTag($element = null)
     {
         if ($element instanceof Element) {
diff --git a/module/fid/src/Helper/SearchTabs.php b/module/fid/src/Helper/SearchTabs.php
index 5ee9dc96cb426982ccebe580ca199db1746519f5..f7d5deccd042345b5282570612e16a5b6744ca16 100644
--- a/module/fid/src/Helper/SearchTabs.php
+++ b/module/fid/src/Helper/SearchTabs.php
@@ -6,6 +6,7 @@
  *
  * Copyright (C) Villanova University 2010.
  * Copyright (C) The National Library of Finland 2015-2016.
+ * Copyright (C) 2021 Leipzig University Library
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2,
@@ -52,7 +53,8 @@ class SearchTabs extends \VuFind\View\Helper\Root\SearchTabs
      */
     protected function createBasicTab($id, $class, $label, $newUrl, $permissionName)
     {
-        $retval = parent::createBasicTab($id, $class, $label, $newUrl, $permissionName);
+        $retval
+            = parent::createBasicTab($id, $class, $label, $newUrl, $permissionName);
         $retval['hiddenFilters'] = $this->helper->getTabFilterConfig()[$id] ?? null;
 
         return $retval;
@@ -90,7 +92,8 @@ class SearchTabs extends \VuFind\View\Helper\Root\SearchTabs
      */
     protected function createHomeTab($id, $class, $label, $filters, $permissionName)
     {
-        $retval = parent::createHomeTab($id, $class, $label, $filters, $permissionName);
+        $retval
+            = parent::createHomeTab($id, $class, $label, $filters, $permissionName);
         $retval['hiddenFilters'] = $this->helper->getTabFilterConfig()[$id] ?? null;
 
         return $retval;
diff --git a/module/fid/src/Helper/TranslatorDelegator.php b/module/fid/src/Helper/TranslatorDelegator.php
index 66735db524edf8612343691f6ae03e662331618a..d63177de76504e54937da876bad70db9afc6b66a 100644
--- a/module/fid/src/Helper/TranslatorDelegator.php
+++ b/module/fid/src/Helper/TranslatorDelegator.php
@@ -1,7 +1,11 @@
 <?php
 /**
+ * Translator Delegator
+ *
  * Copyright (C) 2019 Leipzig University Library
  *
+ * PHP version 7
+ *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation.
@@ -15,16 +19,37 @@
  * with this program; if not, write to the Free Software Foundation, Inc.,
  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  *
- * @author  Robert Lange <lange@ub.uni-leipzig.de>
- * @license http://opensource.org/licenses/gpl-2.0.php GNU GPLv2
+ * @category VuFind
+ * @package  View_Helpers
+ * @author   Robert Lange <lange@ub.uni-leipzig.de>
+ * @license  http://opensource.org/licenses/gpl-2.0.php GNU General Public License
+ * @link     https://vufind.org/wiki/development Wiki
  */
 namespace fid\Helper;
 
 use Psr\Container\ContainerInterface;
 use Zend\I18n\Translator\Resources;
 
+/**
+ * Translator Delegator
+ *
+ * @category VuFind
+ * @package  View_Helpers
+ * @author   Robert Lange <lange@ub.uni-leipzig.de>
+ * @license  http://opensource.org/licenses/gpl-2.0.php GNU General Public License
+ * @link     https://vufind.org/wiki/development Wiki
+ */
 class TranslatorDelegator
 {
+    /**
+     * Invoke method for creating translator object.
+     *
+     * @param ContainerInterface $container Container
+     * @param $name      Class name
+     * @param callable           $callback  Callback function
+     *
+     * @return false|mixed
+     */
     public function __invoke(
         ContainerInterface $container,
         $name,