--- /dev/null
+<?php
+
+/**
+ * Module adds the target-based noreferrer attribute transformation to a tags. It
+ * is enabled by HTML.TargetNoreferrer
+ */
+class HTMLPurifier_HTMLModule_TargetNoreferrer extends HTMLPurifier_HTMLModule
+{
+ /**
+ * @type string
+ */
+ public $name = 'TargetNoreferrer';
+
+ /**
+ * @param HTMLPurifier_Config $config
+ */
+ public function setup($config) {
+ $a = $this->addBlankElement('a');
+ $a->attr_transform_post[] = new HTMLPurifier_AttrTransform_TargetNoreferrer();
+ }
+}