diff --git a/htdocs/admin/invoice.php b/htdocs/admin/invoice.php
index c35809945ba..72c53c740fb 100644
--- a/htdocs/admin/invoice.php
+++ b/htdocs/admin/invoice.php
@@ -133,7 +133,7 @@ if ($action == 'updateMask') {
 } elseif ($action == 'del') {
 	$ret = delDocumentModel($value, $type);
 	if ($ret > 0) {
-		if ($conf->global->FACTURE_ADDON_PDF == "$value") {
+		if (getDolGlobalString('FACTURE_ADDON_PDF') == (string) $value) {
 			dolibarr_del_const($db, 'FACTURE_ADDON_PDF', $conf->entity);
 		}
 	}
@@ -569,7 +569,7 @@ foreach ($dirmodels as $reldir) {
 
 								// Default
 								print '<td class="center">';
-								if ($conf->global->FACTURE_ADDON_PDF == "$name") {
+								if (getDolGlobalString('FACTURE_ADDON_PDF') == (string) $name) {
 									print img_picto($langs->trans("Default"), 'on');
 								} else {
 									print '<a class="reposition" href="'.$_SERVER["PHP_SELF"].'?action=setdoc&token='.newToken().'&value='.urlencode($name).'&scan_dir='.urlencode($module->scandir).'&label='.urlencode($module->name).'" alt="'.$langs->trans("Default").'">'.img_picto($langs->trans("SetAsDefault"), 'off').'</a>';
diff --git a/htdocs/core/modules/fichinter/modules_fichinter.php b/htdocs/core/modules/fichinter/modules_fichinter.php
index 727e1441ab2..b957c35029f 100644
--- a/htdocs/core/modules/fichinter/modules_fichinter.php
+++ b/htdocs/core/modules/fichinter/modules_fichinter.php
@@ -86,6 +86,13 @@ abstract class ModeleNumRefFicheinter extends CommonNumRefGenerator
 	 *	@return string|int<-1,0>    			Next value if OK, <=0 if KO
 	 */
 	abstract public function getNextValue($objsoc = '', $object = '');
+
+	/**
+	 *  Return an example of numbering
+	 *
+	 *  @return     string      Example
+	 */
+	abstract public function getExample();
 }
 
 
diff --git a/htdocs/core/modules/holiday/modules_holiday.php b/htdocs/core/modules/holiday/modules_holiday.php
index 3b5dae7cf95..0bc07d3e73a 100644
--- a/htdocs/core/modules/holiday/modules_holiday.php
+++ b/htdocs/core/modules/holiday/modules_holiday.php
@@ -90,4 +90,11 @@ abstract class ModelNumRefHolidays extends CommonNumRefGenerator
 	 *	@return string|int<-1,0>   			Value if OK, <=0 if KO
 	 */
 	abstract public function getNextValue($objsoc, $holiday);
+
+	/**
+	 *  Return an example of numbering
+	 *
+	 *  @return     string      Example
+	 */
+	abstract public function getExample();
 }
diff --git a/htdocs/core/modules/hrm/modules_evaluation.php b/htdocs/core/modules/hrm/modules_evaluation.php
index c2127651aad..02258ad5fa3 100644
--- a/htdocs/core/modules/hrm/modules_evaluation.php
+++ b/htdocs/core/modules/hrm/modules_evaluation.php
@@ -90,4 +90,12 @@ abstract class ModeleNumRefEvaluation extends CommonNumRefGenerator
 	 *  @return string|int<-1,0>			Value if OK, <=0 if KO
 	 */
 	abstract public function getNextValue($object);
+
+
+	/**
+	 *  Return an example of numbering
+	 *
+	 *  @return     string      Example
+	 */
+	abstract public function getExample();
 }