add some comment

htdocs/livraison/class/livraison.class.php

@@ -64,7 +64,13 @@ class Livraison extends CommonObject
 	public $ref_customer;
 
 	public $date_delivery;    // Date really received
+
+	/**
+     * @var integer|string date_creation
+     */
 	public $date_creation;
+
+
 	public $date_valid;
 	public $model_pdf;
 

htdocs/loan/class/loan.class.php

@@ -63,7 +63,13 @@ class Loan extends CommonObject
 	public $account_capital;
 	public $account_insurance;
 	public $account_interest;
+
+	/**
+     * @var integer|string date_creation
+     */
 	public $date_creation;
+
+
 	public $date_modification;
 	public $date_validation;
 

htdocs/mrp/class/mo.class.php

@@ -121,7 +121,13 @@ class Mo extends CommonObject
 	public $fk_soc;
 	public $note_public;
 	public $note_private;
+
+	/**
+	 * @var integer|string date_creation
+	 */
 	public $date_creation;
+
+
 	public $tms;
 	public $fk_user_creat;
 	public $fk_user_modif;

htdocs/product/class/product.class.php

@@ -325,7 +325,12 @@ class Product extends CommonObject
     public $imgWidth;
     public $imgHeight;
 
+    /**
+     * @var integer|string date_creation
+     */
     public $date_creation;
+
+
     public $date_modification;
 
     //! Id du fournisseur