diff --git a/application/classes/Model/Client.php b/application/classes/Model/Client.php
index 3f8d632..2904410 100644
--- a/application/classes/Model/Client.php
+++ b/application/classes/Model/Client.php
@@ -1,3 +1,46 @@
 <?php defined('SYSPATH') OR die('No direct access allowed.');
+/**
+ * Client model.
+ * Client is just a subscriber at the moment.
+ * @package Models
+ * @author Oreolek
+ **/
 class Model_Client extends ORM {
+  protected $has_many = array(
+    'subscription'
+  );
+  
+  /**
+   * @return array validation rules
+   **/
+  public function rules()
+	{
+		return array(
+      'email' => array(
+				array('not_empty'),
+				array('email'),
+				array('min_length', array(':value', 5)),
+      ),
+      'name' => array(
+				array('not_empty'),
+				array('min_length', array(':value', 5)),
+      ),
+      'token' => array(
+				array('not_empty'),
+        array('numeric')
+      )
+		);
+	}
+
+  /**
+   * Array of field labels.
+   * Used in forms.
+   **/
+  protected $_labels = array(
+    'email' => 'Email',
+    'name' => 'Name',
+    'token' => 'Subscription token'
+  );
+
+
 }
diff --git a/application/classes/Model/Letter.php b/application/classes/Model/Letter.php
index 5c3d54d..3542588 100644
--- a/application/classes/Model/Letter.php
+++ b/application/classes/Model/Letter.php
@@ -1,3 +1,38 @@
 <?php defined('SYSPATH') OR die('No direct access allowed.');
+/**
+ * Electronic letter model.
+ * Stores HTML to be placed in e-mail template.
+ * @package Models
+ * @author Oreolek
+ **/
 class Model_Letter extends ORM {
+  protected $belongs_to = array(
+    'subscription'
+  );
+  
+  /**
+   * @return array validation rules
+   **/
+  public function rules()
+	{
+		return array(
+      'text' => array(
+				array('not_empty'),
+				array('min_length', array(':value', 20)),
+      ),
+      'order' => array(
+        array('numeric')
+      )
+		);
+	}
+
+  /**
+   * Array of field labels.
+   * Used in forms.
+   **/
+  protected $_labels = array(
+    'text' => 'Message text',
+    'order' => 'Message order'
+  );
+
 }
diff --git a/application/classes/Model/Subscription.php b/application/classes/Model/Subscription.php
index a8341fc..169749e 100644
--- a/application/classes/Model/Subscription.php
+++ b/application/classes/Model/Subscription.php
@@ -1,3 +1,45 @@
 <?php defined('SYSPATH') OR die('No direct access allowed.');
+/**
+ * Subscription model.
+ * Subscription is an ordered collection of letters.
+ * It has a period in days. Every <period> days a client receives a letter from the collection.
+ * @package Models
+ * @author Oreolek
+ **/
 class Model_Subscription extends ORM {
+
+  /**
+   * @return array validation rules
+   **/
+  public function rules()
+	{
+		return array(
+      'title' => array(
+				array('not_empty'),
+				array('min_length', array(':value', 4)),
+				array('max_length', array(':value', 100)),
+      )
+      'description' => array(
+				array('not_empty'),
+				array('min_length', array(':value', 20)),
+      ),
+      'period' => array(
+        array('numeric')
+      ),
+      'price' => array(
+        array('numeric')
+      )
+		);
+	}
+
+  /**
+   * Array of field labels.
+   * Used in forms.
+   **/
+  protected $_labels = array(
+    'title' => 'Title',
+    'price' => 'Subscription price',
+    'period' => 'Mailing period (in days)',
+    'description' => 'Description (for the clients)'
+  );
 }
diff --git a/application/classes/Model/Task.php b/application/classes/Model/Task.php
index e5519c5..407c0dc 100644
--- a/application/classes/Model/Task.php
+++ b/application/classes/Model/Task.php
@@ -1,3 +1,43 @@
 <?php defined('SYSPATH') OR die('No direct access allowed.');
+/**
+ * Task model.
+ * Task is a job to send the next letter in a subscription.
+ * @package Models
+ * @author Oreolek
+ **/
 class Model_Task extends ORM {
+  const STATUS_UNKNOWN = 0;
+  const STATUS_PENDING = 1;
+  const STATUS_SENDING = 2;
+  const STATUS_SENT = 3;
+
+  protected $has_many = array(
+    'letter',
+    'client'
+  );
+  
+  /**
+   * @return array validation rules
+   **/
+  public function rules()
+	{
+		return array(
+      'date' => array(
+				array('not_empty'),
+				array('date'),
+      ),
+      'status' => array(
+        array('numeric')
+      )
+		);
+	}
+
+  /**
+   * Array of field labels.
+   * Used in forms.
+   **/
+  protected $_labels = array(
+    'date' => 'Mailing date',
+    'status' => 'Status'
+  );
 }
diff --git a/application/i18n/ru.php b/application/i18n/ru.php
index 98975e7..d2cccee 100644
--- a/application/i18n/ru.php
+++ b/application/i18n/ru.php
@@ -4,5 +4,15 @@ return array(
   'User login' => 'Вход пользователя',
   'Authorization error. Please check user login and password.' => 'Ошибка авторизации. Проверьте правильность имени пользователя и пароля.',
   'Username' => 'Имя пользователя',
-  'Password' => 'Пароль'
+  'Password' => 'Пароль',
+  'Message text' => 'Текст сообщения',
+  'Message order' => 'Порядок сообщения',
+  'Title' => 'Название',
+  'Subscription price' => 'Цена подписки',
+  'Mailing period (in days)' => 'Период рассылки (в днях)',
+  'Description (for the clients)' => 'Описание (для клиентов)',
+  'Email' => 'Email',
+  'Subscription token' => 'Токен подписки',
+  'Mailing date' => 'Дата отправки',
+  'Status' => 'Статус'
 );
diff --git a/model.mwb b/model.mwb
index 51fb208..7c1a5ab 100644
Binary files a/model.mwb and b/model.mwb differ