diff --git a/cli/sync.php b/cli/sync.php
index c120ef1..e8d07b4 100644
--- a/cli/sync.php
+++ b/cli/sync.php
@@ -15,28 +15,18 @@
 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
 
 /**
- * CLI sync for full OSS synchronisation.
+ * IServ enrolment plugin implementation
  *
- * This script is meant to be called from a cronjob to sync moodle with the OSS
- * server to pickup groups as moodle global groups (cohorts).
- *
- * Sample cron entry:
- * # 5 minutes past every full hour
- * 5 * * * * $sudo -u www-data /usr/bin/php /var/www/moodle/enrol/oss/cli/sync.php
- *
- * Notes:
- *   - it is required to use the web server account when executing PHP CLI scripts
- *   - you need to change the "www-data" to match the apache user account
- *   - use "su" if "sudo" not available
- *   - If you have a large number of users, you may want to raise the memory limits
- *     by passing -d momory_limit=256M
- *   - For debugging & better logging, you are encouraged to use in the command line:
- *     -d log_errors=1 -d error_reporting=E_ALL -d display_errors=0 -d html_errors=0
+ * This plugin synchronizes courses and their enrolments with an IServ school server.
+ * Based partially on the OSS plugin by Frank Schütte
  *
  * @package    enrol
- * @subpackage oss
- * @author     Frank Schütte - test script
- * @copyright  2012 Frank Schütte <fschuett@gymnasium-himmelsthuer.de>
+ * @subpackage iserv
+ * @author     Jonas Lührig based on code by Frank Schütte based on code by Iñaki Arenaza
+ * @copyright  1999 onwards Martin Dougiamas {@link http://moodle.com}
+ * @copyright  2010 Iñaki Arenaza <iarenaza@eps.mondragon.edu>
+ * @copyright  2020 Frank Schütte <fschuett@gymhim.de>
+ * @copyright  2023 Gruelag GmbH <buero@gruelag.de>
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 
diff --git a/db/install.php b/db/install.php
index a60dd95..43c5a7e 100644
--- a/db/install.php
+++ b/db/install.php
@@ -14,6 +14,22 @@
 // You should have received a copy of the GNU General Public License
 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
 
+/**
+ * IServ enrolment plugin implementation
+ *
+ * This plugin synchronizes courses and their enrolments with an IServ school server.
+ * Based partially on the OSS plugin by Frank Schütte
+ *
+ * @package    enrol
+ * @subpackage iserv
+ * @author     Jonas Lührig based on code by Frank Schütte based on code by Iñaki Arenaza
+ * @copyright  1999 onwards Martin Dougiamas {@link http://moodle.com}
+ * @copyright  2010 Iñaki Arenaza <iarenaza@eps.mondragon.edu>
+ * @copyright  2020 Frank Schütte <fschuett@gymhim.de>
+ * @copyright  2023 Gruelag GmbH <buero@gruelag.de>
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+
 defined('MOODLE_INTERNAL') || die();
 
 function xmldb_enrol_iserv_install() {
diff --git a/db/tasks.php b/db/tasks.php
index fc38ace..bc110df 100644
--- a/db/tasks.php
+++ b/db/tasks.php
@@ -22,6 +22,22 @@
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 
+/**
+ * IServ enrolment plugin implementation
+ *
+ * This plugin synchronizes courses and their enrolments with an IServ school server.
+ * Based partially on the OSS plugin by Frank Schütte
+ *
+ * @package    enrol
+ * @subpackage iserv
+ * @author     Jonas Lührig based on code by Frank Schütte based on code by Iñaki Arenaza
+ * @copyright  1999 onwards Martin Dougiamas {@link http://moodle.com}
+ * @copyright  2010 Iñaki Arenaza <iarenaza@eps.mondragon.edu>
+ * @copyright  2020 Frank Schütte <fschuett@gymhim.de>
+ * @copyright  2023 Gruelag GmbH <buero@gruelag.de>
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+
 defined('MOODLE_INTERNAL') || die();
 
 $tasks = array(
diff --git a/db/upgrade.php b/db/upgrade.php
index fb2d132..8a188b1 100644
--- a/db/upgrade.php
+++ b/db/upgrade.php
@@ -15,6 +15,22 @@
 // You should have received a copy of the GNU General Public License
 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
 
+/**
+ * IServ enrolment plugin implementation
+ *
+ * This plugin synchronizes courses and their enrolments with an IServ school server.
+ * Based partially on the OSS plugin by Frank Schütte
+ *
+ * @package    enrol
+ * @subpackage iserv
+ * @author     Jonas Lührig based on code by Frank Schütte based on code by Iñaki Arenaza
+ * @copyright  1999 onwards Martin Dougiamas {@link http://moodle.com}
+ * @copyright  2010 Iñaki Arenaza <iarenaza@eps.mondragon.edu>
+ * @copyright  2020 Frank Schütte <fschuett@gymhim.de>
+ * @copyright  2023 Gruelag GmbH <buero@gruelag.de>
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+
 function xmldb_enrol_iserv_upgrade($oldversion) {
     global $CFG, $DB;
     require_once($CFG->libdir . '/accesslib.php');
diff --git a/settings_callbacks.php b/settings_callbacks.php
index 8415977..3605e30 100644
--- a/settings_callbacks.php
+++ b/settings_callbacks.php
@@ -38,8 +38,6 @@ lear<?php
 function enrol_iserv_settings_courses_category_name_updated ($value = "") {
     global $CFG;
 
-    file_put_contents ("/tmp/test.txt", "here {$value}");
-
     require_once "{$CFG -> dirroot}/enrol/iserv/lib.php";
 
     $enrol = enrol_get_plugin('iserv');