diff --git a/core/lib/Drupal/Core/Validation/Annotation/Constraint.php b/core/lib/Drupal/Core/Validation/Annotation/Constraint.php
index 85c4344..4010e76 100644
--- a/core/lib/Drupal/Core/Validation/Annotation/Constraint.php
+++ b/core/lib/Drupal/Core/Validation/Annotation/Constraint.php
@@ -12,7 +12,14 @@
 /**
  * Defines a validation constraint annotation object.
  *
+ * Plugin Namespace: Plugin\Validation\Constraint
+ *
+ * For a working example, see \Drupal\Core\Validation\Plugin\Validation\Constraint\LengthConstraint
+ *
  * @see \Drupal\Core\Validation\ConstraintManager
+ * @see \Symfony\Component\Validator\Constraint
+ * @see hook_validation_constraint_alter()
+ * @see plugin_api
  *
  * @Annotation
  */