diff --git a/src/Mailgun/Lists/OptInHandler.php b/src/Mailgun/Lists/OptInHandler.php
index 3037dcc..d929134 100644
--- a/src/Mailgun/Lists/OptInHandler.php
+++ b/src/Mailgun/Lists/OptInHandler.php
@@ -6,17 +6,20 @@ use Mailgun\Messages\Exceptions\InvalidParameter;
 use Mailgun\Messages\Exceptions\TooManyParameters;
 use Mailgun\Messages\Expcetions\InvalidParameterType;
 
-/* 
-   This class is used for creating a unique hash for 
-   mailing list subscription double-opt in requests.
-*/
-
+/**
+ * This class is used for creating a unique hash for
+ * mailing list subscription double-opt in requests.
+ *
+ * @link https://github.com/mailgun/mailgun-php/blob/master/src/Mailgun/Lists/README.md
+ */
 class OptInHandler{
 
-	function __construct(){
-		
-	}
-	
+    /**
+     * @param string $mailingList
+     * @param string $secretAppId
+     * @param string $recipientAddress
+     * @return string
+     */
 	public function generateHash($mailingList, $secretAppId, $recipientAddress){
 		$innerPayload = array('r' => $recipientAddress, 'l' => $mailingList);
 		$encodedInnerPayload = base64_encode(json_encode($innerPayload));
@@ -27,6 +30,11 @@ class OptInHandler{
 		return urlencode(base64_encode(json_encode($outerPayload)));
 	}
 
+    /**
+     * @param string $secretAppId
+     * @param string $uniqueHash
+     * @return array|bool
+     */
 	public function validateHash($secretAppId, $uniqueHash){
 		$decodedOuterPayload = json_decode(base64_decode(urldecode($uniqueHash)), true);