diff --git a/htdocs/admin/ihm.php b/htdocs/admin/ihm.php
index 23e7cc96363..f2312ee042f 100644
--- a/htdocs/admin/ihm.php
+++ b/htdocs/admin/ihm.php
@@ -53,29 +53,30 @@ $searchformmodule=array('Module1Name','Module1Name','Module50Name','Module50Name
 
 if ($action == 'update')
 {
-	dolibarr_set_const($db, "MAIN_LANG_DEFAULT",       $_POST["main_lang_default"],'chaine',0,'',$conf->entity);
-	dolibarr_set_const($db, "MAIN_MULTILANGS",         $_POST["main_multilangs"],'chaine',0,'',$conf->entity);
-	dolibarr_set_const($db, "MAIN_SIZE_LISTE_LIMIT",   $_POST["main_size_liste_limit"],'chaine',0,'',$conf->entity);
-	dolibarr_set_const($db, "MAIN_DISABLE_JAVASCRIPT", $_POST["main_disable_javascript"],'chaine',0,'',$conf->entity);
-	dolibarr_set_const($db, "MAIN_BUTTON_HIDE_UNAUTHORIZED", $_POST["MAIN_BUTTON_HIDE_UNAUTHORIZED"],'chaine',0,'',$conf->entity);
-	dolibarr_set_const($db, "MAIN_START_WEEK",         $_POST["MAIN_START_WEEK"],'chaine',0,'',$conf->entity);
-	dolibarr_set_const($db, "MAIN_DEFAULT_WORKING_DAYS",  $_POST["MAIN_DEFAULT_WORKING_DAYS"],'chaine',0,'',$conf->entity);
-	dolibarr_set_const($db, "MAIN_DEFAULT_WORKING_HOURS", $_POST["MAIN_DEFAULT_WORKING_HOURS"],'chaine',0,'',$conf->entity);
-	dolibarr_set_const($db, "MAIN_SHOW_LOGO",          $_POST["MAIN_SHOW_LOGO"],'chaine',0,'',$conf->entity);
-	dolibarr_set_const($db, "MAIN_FIRSTNAME_NAME_POSITION",          $_POST["MAIN_FIRSTNAME_NAME_POSITION"],'chaine',0,'',$conf->entity);
+	dolibarr_set_const($db, "MAIN_LANG_DEFAULT",				$_POST["main_lang_default"],'chaine',0,'',$conf->entity);
+	dolibarr_set_const($db, "MAIN_MULTILANGS",					$_POST["main_multilangs"],'chaine',0,'',$conf->entity);
+	dolibarr_set_const($db, "MAIN_SIZE_LISTE_LIMIT",			$_POST["main_size_liste_limit"],'chaine',0,'',$conf->entity);
+	dolibarr_set_const($db, "MAIN_DISABLE_JAVASCRIPT",			$_POST["main_disable_javascript"],'chaine',0,'',$conf->entity);
+	dolibarr_set_const($db, "MAIN_BUTTON_HIDE_UNAUTHORIZED",	$_POST["MAIN_BUTTON_HIDE_UNAUTHORIZED"],'chaine',0,'',$conf->entity);
+	dolibarr_set_const($db, "MAIN_START_WEEK",					$_POST["MAIN_START_WEEK"],'chaine',0,'',$conf->entity);
+	dolibarr_set_const($db, "MAIN_DEFAULT_WORKING_DAYS",		$_POST["MAIN_DEFAULT_WORKING_DAYS"],'chaine',0,'',$conf->entity);
+	dolibarr_set_const($db, "MAIN_DEFAULT_WORKING_HOURS",		$_POST["MAIN_DEFAULT_WORKING_HOURS"],'chaine',0,'',$conf->entity);
+	dolibarr_set_const($db, "MAIN_SHOW_LOGO",					$_POST["MAIN_SHOW_LOGO"],'chaine',0,'',$conf->entity);
+	dolibarr_set_const($db, "MAIN_ACTIVATE_HTML5",				$_POST["MAIN_ACTIVATE_HTML5"],'chaine',0,'',$conf->entity);
+	dolibarr_set_const($db, "MAIN_FIRSTNAME_NAME_POSITION",		$_POST["MAIN_FIRSTNAME_NAME_POSITION"],'chaine',0,'',$conf->entity);
 
-	dolibarr_set_const($db, "MAIN_THEME",              $_POST["main_theme"],'chaine',0,'',$conf->entity);
+	dolibarr_set_const($db, "MAIN_THEME",						$_POST["main_theme"],'chaine',0,'',$conf->entity);
 
-	dolibarr_set_const($db, "MAIN_SEARCHFORM_CONTACT", $_POST["MAIN_SEARCHFORM_CONTACT"],'chaine',0,'',$conf->entity);
-	dolibarr_set_const($db, "MAIN_SEARCHFORM_SOCIETE", $_POST["MAIN_SEARCHFORM_SOCIETE"],'chaine',0,'',$conf->entity);
-	dolibarr_set_const($db, "MAIN_SEARCHFORM_PRODUITSERVICE",$_POST["MAIN_SEARCHFORM_PRODUITSERVICE"],'chaine',0,'',$conf->entity);
+	dolibarr_set_const($db, "MAIN_SEARCHFORM_CONTACT",			$_POST["MAIN_SEARCHFORM_CONTACT"],'chaine',0,'',$conf->entity);
+	dolibarr_set_const($db, "MAIN_SEARCHFORM_SOCIETE",			$_POST["MAIN_SEARCHFORM_SOCIETE"],'chaine',0,'',$conf->entity);
+	dolibarr_set_const($db, "MAIN_SEARCHFORM_PRODUITSERVICE",	$_POST["MAIN_SEARCHFORM_PRODUITSERVICE"],'chaine',0,'',$conf->entity);
 	dolibarr_set_const($db, "MAIN_SEARCHFORM_PRODUITSERVICE_SUPPLIER",$_POST["MAIN_SEARCHFORM_PRODUITSERVICE_SUPPLIER"],'chaine',0,'',$conf->entity);
-	dolibarr_set_const($db, "MAIN_SEARCHFORM_ADHERENT",$_POST["MAIN_SEARCHFORM_ADHERENT"],'chaine',0,'',$conf->entity);
+	dolibarr_set_const($db, "MAIN_SEARCHFORM_ADHERENT",			$_POST["MAIN_SEARCHFORM_ADHERENT"],'chaine',0,'',$conf->entity);
 
-	dolibarr_set_const($db, "MAIN_HELPCENTER_DISABLELINK", $_POST["MAIN_HELPCENTER_DISABLELINK"],'chaine',0,'',0);	// Param for all entities
-	dolibarr_set_const($db, "MAIN_MOTD",                   dol_htmlcleanlastbr($_POST["main_motd"]),'chaine',0,'',$conf->entity);
-	dolibarr_set_const($db, "MAIN_HOME",                   dol_htmlcleanlastbr($_POST["main_home"]),'chaine',0,'',$conf->entity);
-	dolibarr_set_const($db, "MAIN_HELP_DISABLELINK",       $_POST["MAIN_HELP_DISABLELINK"],'chaine',0,'',0);	    // Param for all entities
+	dolibarr_set_const($db, "MAIN_HELPCENTER_DISABLELINK",		$_POST["MAIN_HELPCENTER_DISABLELINK"],'chaine',0,'',0);	// Param for all entities
+	dolibarr_set_const($db, "MAIN_MOTD",						dol_htmlcleanlastbr($_POST["main_motd"]),'chaine',0,'',$conf->entity);
+	dolibarr_set_const($db, "MAIN_HOME",						dol_htmlcleanlastbr($_POST["main_home"]),'chaine',0,'',$conf->entity);
+	dolibarr_set_const($db, "MAIN_HELP_DISABLELINK",			$_POST["MAIN_HELP_DISABLELINK"],'chaine',0,'',0);	    // Param for all entities
 
 	// This one is not always defined
 	if (isset($_POST["MAIN_USE_PREVIEW_TABS"])) dolibarr_set_const($db, "MAIN_USE_PREVIEW_TABS", $_POST["MAIN_USE_PREVIEW_TABS"],'chaine',0,'',$conf->entity);
@@ -119,7 +120,7 @@ if ($action == 'edit')	// Edit
 
     print_fiche_titre($langs->trans("Language"),'','').'<br>';
     print '<table summary="edit" class="noborder" width="100%">';
-    print '<tr class="liste_titre"><td>'.$langs->trans("Parameter").'</td><td>'.$langs->trans("Value").'</td>';
+    print '<tr class="liste_titre"><td>'.$langs->trans("Parameters").'</td><td>'.$langs->trans("Value").'</td>';
 	print '<td width="20">&nbsp;</td>';
 	print '</tr>';
 
@@ -172,6 +173,17 @@ if ($action == 'edit')	// Edit
     print '</td>';
 	print '<td width="20">&nbsp;</td>';
 	print '</tr>';
+	
+	// Activate Html5 - Developement - Only available on Eldy template
+	if ($conf->global->MAIN_FEATURES_LEVEL == 2 || ! empty($conf->global->MAIN_ACTIVATE_HTML5))
+	{
+		$var=!$var;
+		print '<tr '.$bc[$var].'><td width="35%">'.$langs->trans("EnableHtml5").'</td><td>';
+		print $form->selectyesno('MAIN_ACTIVATE_HTML5',$conf->global->MAIN_ACTIVATE_HTML5,1);
+		print '</td>';
+		print '<td width="20">&nbsp;</td>';
+		print '</tr>';
+	}
 
 	// Max size of lists
     $var=!$var;
@@ -351,6 +363,15 @@ else	// Show
     print '<tr '.$bc[$var].'><td>'.$langs->trans("EnableShowLogo").'</td><td>' . yn($conf->global->MAIN_SHOW_LOGO) . '</td>';
 	print '<td width="20">&nbsp;</td>';
 	print "</tr>";
+	
+	// Activate Html5 - Developement - Only available on Eldy template
+	if ($conf->global->MAIN_FEATURES_LEVEL == 2 || ! empty($conf->global->MAIN_ACTIVATE_HTML5))
+    {
+		$var=!$var;
+		print '<tr '.$bc[$var].'><td>'.$langs->trans("EnableHtml5").'</td><td>' . yn($conf->global->MAIN_ACTIVATE_HTML5) . '</td>';
+		print '<td width="20">&nbsp;</td>';
+		print "</tr>";
+	}
 
 	$var=!$var;
     print '<tr '.$bc[$var].'><td>'.$langs->trans("DefaultMaxSizeList").'</td><td>' . $conf->global->MAIN_SIZE_LISTE_LIMIT . '</td>';
diff --git a/htdocs/langs/en_US/admin.lang b/htdocs/langs/en_US/admin.lang
index a524ff8a5fe..4aee36d73ab 100644
--- a/htdocs/langs/en_US/admin.lang
+++ b/htdocs/langs/en_US/admin.lang
@@ -887,7 +887,8 @@ MessageLogin=Login page message
 PermanentLeftSearchForm=Permanent search form on left menu
 DefaultLanguage=Default language to use (language code)
 EnableMultilangInterface=Enable multilingual interface
-EnableShowLogo=Show logo on left menu 
+EnableShowLogo=Show logo on left menu
+EnableHtml5=Enable Html5 (Developement - Only available on Eldy template)
 SystemSuccessfulyUpdated=Your system has been updated successfully
 CompanyInfo=Company/foundation information
 CompanyIds=Company/foundation identities
diff --git a/htdocs/main.inc.php b/htdocs/main.inc.php
index 87b69b56443..199436eae65 100644
--- a/htdocs/main.inc.php
+++ b/htdocs/main.inc.php
@@ -959,11 +959,11 @@ function top_htmlhead($head, $title='', $disablejs=0, $disablehead=0, $arrayofjs
 
     if (empty($conf->css)) $conf->css = '/theme/eldy/style.css.php';	// If not defined, eldy by default
 
-    //print '<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">';
+    if (empty($conf->global->MAIN_ACTIVATE_HTML5)) print '<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">';
     //print '<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/1999/REC-html401-19991224/strict.dtd">';
     //print '<!DOCTYPE HTML PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">';
     //print '<!DOCTYPE HTML PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">';
-    print '<!DOCTYPE html>';
+    if ($conf->global->MAIN_FEATURES_LEVEL == 2 || ! empty($conf->global->MAIN_ACTIVATE_HTML5)) print '<!DOCTYPE html>'; // Html5 - Developement - Only available on Eldy template
     print "\n";
     if (! empty($conf->global->MAIN_USE_CACHE_MANIFEST)) print '<html lang="'.substr($langs->defaultlang,0,2).'" manifest="'.DOL_URL_ROOT.'/cache.manifest">'."\n";
     else print '<html lang="'.substr($langs->defaultlang,0,2).'">'."\n";