diff --git a/classes/event/notification_received.php b/classes/event/notification_received.php
index cc5dd83..ab5c153 100644
--- a/classes/event/notification_received.php
+++ b/classes/event/notification_received.php
@@ -26,7 +26,9 @@
 
 use tool_emailutils;
 
-
+/**
+ * Event
+ */
 class notification_received extends \core\event\base {
 
     /**
diff --git a/classes/sns_client.php b/classes/sns_client.php
index c7630c5..2321561 100644
--- a/classes/sns_client.php
+++ b/classes/sns_client.php
@@ -15,6 +15,8 @@
 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
 
 /**
+ * Amazon SNS Client Interface
+ *
  * @package    tool_emailutils
  * @copyright  2018 onwards Catalyst IT {@link http://www.catalyst-eu.net/}
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
@@ -45,14 +47,19 @@
  */
 class sns_client {
 
+    /** Subscribe */
     const SUBSCRIPTION_TYPE = 'SubscriptionConfirmation';
 
+    /** Unsubscribe */
     const UNSUBSCRIPTION_TYPE = 'UnsubscribeConfirmation';
 
+    /** Notify */
     const NOTIFICATION_TYPE = 'Notification';
 
+    /** Complaint */
     const COMPLAINT_TYPE = 'Complaint';
 
+    /** Bounce */
     const BOUNCE_TYPE = 'Bounce';
 
     /**
diff --git a/classes/sns_notification.php b/classes/sns_notification.php
index 92808d1..dae6783 100644
--- a/classes/sns_notification.php
+++ b/classes/sns_notification.php
@@ -15,6 +15,8 @@
 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
 
 /**
+ * Amazon SNS Notification Class
+ *
  * @package    tool_emailutils
  * @copyright  2018 onwards Catalyst IT {@link http://www.catalyst-eu.net/}
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
diff --git a/client.php b/client.php
index b25448e..f2a2b5c 100644
--- a/client.php
+++ b/client.php
@@ -15,6 +15,12 @@
 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
 
 /**
+ * An email bounce complaint handler webhook
+ *
+ * This is the endpoint that AWS notifies when it receives a complaint.
+ * This handles the complaint by incrementing the users bounce level and
+ * emiting a Moodle event.
+ *
  * @package    tool_emailutils
  * @copyright  2018 onwards Catalyst IT {@link http://www.catalyst-eu.net/}
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
diff --git a/index.php b/index.php
index 3de9300..05bccd4 100644
--- a/index.php
+++ b/index.php
@@ -15,6 +15,8 @@
 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
 
 /**
+ * Email bounce handler
+ *
  * @package    tool_emailutils
  * @copyright  2019 onwards Catalyst IT {@link http://www.catalyst-eu.net/}
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
diff --git a/lib.php b/lib.php
index 839966f..12be8ed 100644
--- a/lib.php
+++ b/lib.php
@@ -15,12 +15,17 @@
 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
 
 /**
+ * Lib
+ *
  * @package    tool_emailutils
  * @copyright  2018 onwards Catalyst IT {@link http://www.catalyst-eu.net/}
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  * @author     Harry Barnard <harry.barnard@catalyst-eu.net>
  */
 
+/**
+ * This adds a new bulk user action to reset a persons bounce count
+ */
 function tool_emailutils_bulk_user_actions() {
     return [
         'tool_ses_reset_bounces' => new action_link(
diff --git a/version.php b/version.php
index aefbb54..419f85f 100644
--- a/version.php
+++ b/version.php
@@ -15,6 +15,8 @@
 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
 
 /**
+ * Version
+ *
  * @package    tool_emailutils
  * @copyright  2018 onwards Catalyst IT {@link http://www.catalyst-eu.net/}
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later