diff --git a/docs/index.rst b/docs/index.rst
index 808ba76..026ac15 100644
--- a/docs/index.rst
+++ b/docs/index.rst
@@ -218,25 +218,47 @@ Changelog:
 * **1.0.0**: First Version.
 
 
-Meatdata
-------
+Encrypted
+---------
+
+This type is used to properly manage values must be stored safely (e.g. encrypted) in the IS.
+
+
+.. table:: **Encrypted** ``extends`` **Property**
+
+	+-------+--------+--------------------------------------------------------+-------------------------------------+
+	| Name  | Type   | Attributes                                             | Description                         |
+	+=======+========+========================================================+=====================================+
+	| value | String | ``Mandatory:true`` ``ReadOnly:false`` ``NotNull:true`` | The value to store safely in the IS |
+	+-------+--------+--------------------------------------------------------+-------------------------------------+
+
+
+The **Encrypted** current version is 1.0.0.
+
+Changelog:
+
+* **1.0.0**: First Version.
+
+
+Metadata
+--------
 
 This type provides metadata per every IdentifiableElement
 
 
 .. table:: **Metadata** ``extends`` **Property**
 
-	+----------------+--------+----------------------------------------------------------------------------------------------------------------------------------------------------+-----------------------------------------------------------------------------------------------------------------------------------------+
-	| Name           | Type   | Attributes                                                                                                                                         | Description                                                                                                                             |
-	+================+========+====================================================================================================================================================+=========================================================================================================================================+
-	| createdBy      | String | ``Mandatory:true`` ``ReadOnly:true`` ``NotNull:true``                                                                                              | The user that created the Entity or the Relation. It is initialized at Creation Time.                                                   |
-	+----------------+--------+----------------------------------------------------------------------------------------------------------------------------------------------------+-----------------------------------------------------------------------------------------------------------------------------------------+
-	| creationTime   | Date   | ``Mandatory:true`` ``ReadOnly:true`` ``NotNull:true``                                                                                              | Creation time. It is represented in the format yyyy-MM-dd HH:mm:ss.SSS Z.                                                               |
-	+----------------+--------+----------------------------------------------------------------------------------------------------------------------------------------------------+-----------------------------------------------------------------------------------------------------------------------------------------+
-	| lastUpdateBy   | String | ``Mandatory:true`` ``ReadOnly:false`` ``NotNull:true``                                                                                             | The user that made the last update to the Entity or the Relation. At Creation Time, it assumes the same value of createdBy.             |
-	+----------------+--------+----------------------------------------------------------------------------------------------------------------------------------------------------+-----------------------------------------------------------------------------------------------------------------------------------------+
-	| lastUpdateTime | Date   | ``Mandatory:true`` ``ReadOnly:false`` ``NotNull:true``                                                                                             | Last Update time. At creation time it assumes the same value of creationTime. It is represented in the format yyyy-MM-dd HH:mm:ss.SSS Z |
-	+----------------+--------+----------------------------------------------------------------------------------------------------------------------------------------------------+-----------------------------------------------------------------------------------------------------------------------------------------+
+	+----------------+--------+--------------------------------------------------------+-----------------------------------------------------------------------------------------------------------------------------------------+
+	| Name           | Type   | Attributes                                             | Description                                                                                                                             |
+	+================+========+========================================================+=========================================================================================================================================+
+	| createdBy      | String | ``Mandatory:true`` ``ReadOnly:true`` ``NotNull:true``  | The user that created the Entity or the Relation. It is initialized at Creation Time.                                                   |
+	+----------------+--------+--------------------------------------------------------+-----------------------------------------------------------------------------------------------------------------------------------------+
+	| creationTime   | Date   | ``Mandatory:true`` ``ReadOnly:true`` ``NotNull:true``  | Creation time. It is represented in the format yyyy-MM-dd HH:mm:ss.SSS Z.                                                               |
+	+----------------+--------+--------------------------------------------------------+-----------------------------------------------------------------------------------------------------------------------------------------+
+	| lastUpdateBy   | String | ``Mandatory:true`` ``ReadOnly:false`` ``NotNull:true`` | The user that made the last update to the Entity or the Relation. At Creation Time, it assumes the same value of createdBy.             |
+	+----------------+--------+--------------------------------------------------------+-----------------------------------------------------------------------------------------------------------------------------------------+
+	| lastUpdateTime | Date   | ``Mandatory:true`` ``ReadOnly:false`` ``NotNull:true`` | Last Update time. At creation time it assumes the same value of creationTime. It is represented in the format yyyy-MM-dd HH:mm:ss.SSS Z |
+	+----------------+--------+--------------------------------------------------------+-----------------------------------------------------------------------------------------------------------------------------------------+
 
 
 The **Metadata** current version is 1.0.0.
@@ -273,28 +295,6 @@ Changelog:
 * **1.0.0**: First Version;
 
 
-Vault
------
-
-This type is used to properly manage values must be stored safely (e.g. encrypted) in the IS.
-
-
-.. table:: **Vault** ``extends`` **Property**
-
-	+-------+--------+--------------------------------------------------------+-------------------------------------+
-	| Name  | Type   | Attributes                                             | Description                         |
-	+=======+========+========================================================+=====================================+
-	| value | String | ``Mandatory:true`` ``ReadOnly:false`` ``NotNull:true`` | The value to store safely in the IS |
-	+-------+--------+--------------------------------------------------------+-------------------------------------+
-
-
-The **Vault** current version is 1.0.0.
-
-Changelog:
-
-* **1.0.0**: First Version.
-
-
 Entity
 ======
 
@@ -303,13 +303,15 @@ This is the base type for any Entity
 
 .. table:: **Entity**
 
-	+------------+----------+--------------------------------------------------------+--------------------------------------------------------------------------------------------+
-	| Properties                                                                                                                                                                  |
-	+============+==========+========================================================+============================================================================================+
-	| **Name**   | **Type** | **Attributes**                                         | **Description**                                                                            |
-	+------------+----------+--------------------------------------------------------+--------------------------------------------------------------------------------------------+
-	| metadata  | Metadata | ``Mandatory:true`` ``ReadOnly:false`` ``NotNull:true`` | Metadata associated with the instance that is automatically created/updated by the system. |
-	+------------+----------+--------------------------------------------------------+--------------------------------------------------------------------------------------------+
+	+------------+----------+----------------------------------------------------------------------------------------------------------------------------------------------------+--------------------------------------------------------------------------------------------+
+	| Properties                                                                                                                                                                                                                                                              |
+	+============+==========+====================================================================================================================================================+============================================================================================+
+	| **Name**   | **Type** | **Attributes**                                                                                                                                     | **Description**                                                                            |
+	+------------+----------+----------------------------------------------------------------------------------------------------------------------------------------------------+--------------------------------------------------------------------------------------------+
+	| id         | String   | ``Mandatory:true`` ``ReadOnly:true`` ``NotNull:true`` ``Regex:^([a-fA-F0-9]{8}-[a-fA-F0-9]{4}-[a-fA-F0-9]{4}-[a-fA-F0-9]{4}-[a-fA-F0-9]{12}){1}$`` | This UUID is be used to identify the instance univocally.                                  |
+	+------------+----------+----------------------------------------------------------------------------------------------------------------------------------------------------+--------------------------------------------------------------------------------------------+
+	| metadata   | Metadata | ``Mandatory:true`` ``ReadOnly:false`` ``NotNull:true``                                                                                             | Metadata associated with the instance that is automatically created/updated by the system. |
+	+------------+----------+----------------------------------------------------------------------------------------------------------------------------------------------------+--------------------------------------------------------------------------------------------+
 
 
 The **Entity** current version is 1.0.0.