diff --git a/htdocs/core/modules/supplier_invoice/modules_facturefournisseur.php b/htdocs/core/modules/supplier_invoice/modules_facturefournisseur.php
index 5d409dd6c67..3d4e442f6f3 100755
--- a/htdocs/core/modules/supplier_invoice/modules_facturefournisseur.php
+++ b/htdocs/core/modules/supplier_invoice/modules_facturefournisseur.php
@@ -1,6 +1,7 @@
 <?php
 /* Copyright (C) 2010	Juanjo Menent	<jmenent@2byte.es>
  * Copyright (C) 2012	Regis Houssin	<regis.houssin@capnetworks.com>
+ * Copyright (C) 2013   Philippe Grand  <philippe.grand@atoo-net.com>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -20,7 +21,7 @@
 /**
  *		\file       htdocs/core/modules/supplier_invoice/modules_facturefournisseur.php
  *      \ingroup    facture fournisseur
- *      \brief      File that contain parent class for supplier invoices models
+ *      \brief      File that contains parent class for supplier invoices models
  */
 require_once DOL_DOCUMENT_ROOT.'/core/class/commondocgenerator.class.php';
 
@@ -55,6 +56,79 @@ abstract class ModelePDFSuppliersInvoices extends CommonDocGenerator
 
 }
 
+/**
+ *	Parent Class of numbering models of suppliers invoices references
+ */
+abstract class ModeleNumRefSuppliersInvoices
+{
+	var $error='';
+
+	/**  Return if a model can be used or not
+	 *
+	 *   @return	boolean     true if model can be used
+	 */
+	function isEnabled()
+	{
+		return true;
+	}
+
+	/**  Returns the default description of the model numbering
+	 *
+	 *   @return    string      Description Text
+	 */
+	function info()
+	{
+		global $langs;
+		$langs->load("invoices");
+		return $langs->trans("NoDescription");
+	}
+
+	/**   Returns a numbering example
+	 *
+	 *    @return   string      Example
+	 */
+	function getExample()
+	{
+		global $langs;
+		$langs->load("invoices");
+		return $langs->trans("NoExample");
+	}
+
+	/**  Tests if the numbers already in force in the database do not cause conflicts that would prevent this numbering.
+	 *
+	 *   @return	boolean     false if conflict, true if ok
+	 */
+	function canBeActivated()
+	{
+		return true;
+	}
+
+	/**  Returns next value assigned
+	 *
+	 *   @return     string      Valeur
+	 */
+	function getNextValue()
+	{
+		global $langs;
+		return $langs->trans("NotAvailable");
+	}
+
+	/**   Returns version of the model numbering
+	 *
+	 *    @return     string      Value
+	 */
+	function getVersion()
+	{
+		global $langs;
+		$langs->load("admin");
+
+		if ($this->version == 'development') return $langs->trans("VersionDevelopment");
+		if ($this->version == 'experimental') return $langs->trans("VersionExperimental");
+		if ($this->version == 'dolibarr') return DOL_VERSION;
+		return $langs->trans("NotAvailable");
+	}
+}
+
 /**
  *	Create a document onto disk according to template module.
  *
@@ -168,4 +242,4 @@ function supplier_invoice_pdf_create($db, $object, $modele, $outputlangs, $hided
 	}
 }
 
-?>
+?>
\ No newline at end of file