diff --git a/docs/lists/ch06/06-03.txt b/docs/lists/ch06/06-03.txt
new file mode 100644
index 0000000..98d6b25
--- /dev/null
+++ b/docs/lists/ch06/06-03.txt
@@ -0,0 +1,57 @@
+...
+use Doctrine\ORM\Mapping as ORM;
+...
+/**
+ * Inquiry
+ *
+ * @ORM\Table(name="inquiry")
+ * @ORM\Entity(repositoryClass="AppBundle\Entity\InquiryRepository")
+ */
+class Inquiry
+{
+    ...
+    /**
+     * @var string
+     *
+     * @ORM\Column(name="name", type="string", length=30)
+     * @Assert\NotBlank()
+     * @Assert\Length(max=30)
+     */
+    private $name;
+
+    /**
+     * @var string
+     *
+     * @ORM\Column(name="email", type="string", length=100)
+     * @Assert\NotBlank()
+     * @Assert\Length(max=100)
+     * @Assert\Email()
+     */
+    private $email;
+
+    /**
+     * @var string
+     *
+     * @ORM\Column(name="tel", type="string", length=20, nullable=true)
+     * @Assert\Length(max=20)
+     * @Assert\Regex(pattern="/^[0-9-]+$/")
+     */
+    private $tel;
+
+    /**
+     * @var string
+     *
+     * @ORM\Column(name="type", type="string", length=20)
+     * @Assert\NotBlank()
+     */
+    private $type;
+
+    /**
+     * @var string
+     *
+     * @ORM\Column(name="content", type="text")
+     * @Assert\NotBlank()
+     */
+    private $content;
+    ...
+}
diff --git a/src/AppBundle/Entity/Inquiry.php b/src/AppBundle/Entity/Inquiry.php
index 4f318b0..1e241e2 100644
--- a/src/AppBundle/Entity/Inquiry.php
+++ b/src/AppBundle/Entity/Inquiry.php
@@ -3,6 +3,7 @@
 namespace AppBundle\Entity;
 
 use Doctrine\ORM\Mapping as ORM;
+use Symfony\Component\Validator\Constraints As Assert;
 
 /**
  * Inquiry
@@ -25,6 +26,8 @@ class Inquiry
      * @var string
      *
      * @ORM\Column(name="name", type="string", length=30)
+     * @Assert\NotBlank()
+     * @Assert\Length(max=30)
      */
     private $name;
 
@@ -32,6 +35,9 @@ class Inquiry
      * @var string
      *
      * @ORM\Column(name="email", type="string", length=100)
+     * @Assert\NotBlank()
+     * @Assert\Length(max=100)
+     * @Assert\Email()
      */
     private $email;
 
@@ -39,6 +45,8 @@ class Inquiry
      * @var string
      *
      * @ORM\Column(name="tel", type="string", length=20, nullable=true)
+     * @Assert\Length(max=20)
+     * @Assert\Regex(pattern="/^[0-9-]+$/")
      */
     private $tel;
 
@@ -46,6 +54,7 @@ class Inquiry
      * @var string
      *
      * @ORM\Column(name="type", type="string", length=20)
+     * @Assert\NotBlank()
      */
     private $type;
 
@@ -53,6 +62,7 @@ class Inquiry
      * @var string
      *
      * @ORM\Column(name="content", type="text")
+     * @Assert\NotBlank()
      */
     private $content;