diff --git a/IdentityServer/v8/UserManagement/PasswordRegistration/PasswordRegistration/StringExtensions.cs b/IdentityServer/v8/UserManagement/PasswordRegistration/PasswordRegistration/StringExtensions.cs
index e0c664c5..352f78d1 100644
--- a/IdentityServer/v8/UserManagement/PasswordRegistration/PasswordRegistration/StringExtensions.cs
+++ b/IdentityServer/v8/UserManagement/PasswordRegistration/PasswordRegistration/StringExtensions.cs
@@ -5,8 +5,14 @@ namespace PasswordRegistration;
 
 internal static class StringExtensions
 {
-    /// <summary>
-    /// Takes an email string and puts it into the way it's stored in the database
-    /// </summary>
+    /// Duende User Management respects the email RFC, where the part before the @ is case-sensitive
+    /// and the domain itself is not.
+    ///
+    /// aaa@aaa.com and AaA@aaa.com are different email addresses.
+    ///
+    /// In this sample, we are normalizing the email address so that the sample app treats
+    /// these 2 example emails as the same.
+    /// 
+    /// While it differs from the RFC, it's what users expect.
     public static string NormalizeEmail(this string email) => email.ToLowerInvariant();
 }