diff --git a/recaptcha_enterprise/demosite/app/controllers/controller.js b/recaptcha_enterprise/demosite/app/controllers/controller.js
index 02beff5258..59876faeed 100644
--- a/recaptcha_enterprise/demosite/app/controllers/controller.js
+++ b/recaptcha_enterprise/demosite/app/controllers/controller.js
@@ -249,6 +249,7 @@ const onCommentSubmit = async (req, res) => {
 };
 
 // Classify the action as BAD/ NOT_BAD based on conditions specified.
+// See https://cloud.google.com/recaptcha/docs/interpret-assessment-website
 const checkForBadAction = function (assessmentResponse, recaptchaAction) {
   let label = Label.NOT_BAD;
   let reason = '';