diff --git a/htdocs/core/class/html.formmail.class.php b/htdocs/core/class/html.formmail.class.php
index 57830e7d661..e08d1637107 100644
--- a/htdocs/core/class/html.formmail.class.php
+++ b/htdocs/core/class/html.formmail.class.php
@@ -1617,7 +1617,14 @@ class ModelMail
 	 */
 	public $label;
 
+	/**
+	 * @var string Model mail topic
+	 */
 	public $topic;
+
+	/**
+	 * @var string Model mail content
+	 */
 	public $content;
 	public $content_lines;
 	public $lang;