diff --git a/htdocs/core/lib/project.lib.php b/htdocs/core/lib/project.lib.php
index d3285869752..722f99d3b69 100644
--- a/htdocs/core/lib/project.lib.php
+++ b/htdocs/core/lib/project.lib.php
@@ -31,16 +31,17 @@ require_once DOL_DOCUMENT_ROOT.'/projet/class/project.class.php';
  * Prepare array with list of tabs
  *
  * @param	Project	$project	Object related to tabs
+ * @param	string	$moreparam	More param on url
  * @return	array				Array of tabs to show
  */
-function project_prepare_head(Project $project)
+function project_prepare_head(Project $project, $moreparam = '')
 {
 	global $db, $langs, $conf, $user;
 
 	$h = 0;
 	$head = array();
 
-	$head[$h][0] = DOL_URL_ROOT.'/projet/card.php?id='.$project->id;
+	$head[$h][0] = DOL_URL_ROOT.'/projet/card.php?id='.((int) $project->id).($moreparam ? '&'.$moreparam : '');
 	$head[$h][1] = $langs->trans("Project");
 	$head[$h][2] = 'project';
 	$h++;
@@ -56,7 +57,7 @@ function project_prepare_head(Project $project)
 		$nbContacts = count($project->liste_contact(-1, 'internal')) + count($project->liste_contact(-1, 'external'));
 		dol_setcache($cachekey, $nbContacts, 120);	// If setting cache fails, this is not a problem, so we do not test result.
 	}
-	$head[$h][0] = DOL_URL_ROOT.'/projet/contact.php?id='.$project->id;
+	$head[$h][0] = DOL_URL_ROOT.'/projet/contact.php?id='.((int) $project->id).($moreparam ? '&'.$moreparam : '');
 	$head[$h][1] = $langs->trans("ProjectContact");
 	if ($nbContacts > 0) {
 		$head[$h][1] .= '<span class="badge marginleftonlyshort">'.$nbContacts.'</span>';
@@ -80,7 +81,7 @@ function project_prepare_head(Project $project)
 			$nbTasks = count($taskstatic->getTasksArray(0, 0, $project->id, 0, 0));
 			dol_setcache($cachekey, $nbTasks, 120);	// If setting cache fails, this is not a problem, so we do not test result.
 		}
-		$head[$h][0] = DOL_URL_ROOT.'/projet/tasks.php?id='.$project->id;
+		$head[$h][0] = DOL_URL_ROOT.'/projet/tasks.php?id='.((int) $project->id).($moreparam ? '&'.$moreparam : '');
 		$head[$h][1] = $langs->trans("Tasks");
 		if ($nbTasks > 0) {
 			$head[$h][1] .= '<span class="badge marginleftonlyshort">'.($nbTasks).'</span>';
@@ -113,7 +114,7 @@ function project_prepare_head(Project $project)
 			}
 		}
 
-		$head[$h][0] = DOL_URL_ROOT.'/projet/tasks/time.php?withproject=1&projectid='.urlencode($project->id);
+		$head[$h][0] = DOL_URL_ROOT.'/projet/tasks/time.php?withproject=1&projectid='.((int) $project->id).($moreparam ? '&'.$moreparam : '');
 		$head[$h][1] = $langs->trans("TimeSpent");
 		if ($nbTimeSpent > 0) {
 			$head[$h][1] .= '<span class="badge marginleftonlyshort">...</span>';
diff --git a/htdocs/eventorganization/conferenceorboothattendee_card.php b/htdocs/eventorganization/conferenceorboothattendee_card.php
index 329b54d5eda..8a2298124c9 100644
--- a/htdocs/eventorganization/conferenceorboothattendee_card.php
+++ b/htdocs/eventorganization/conferenceorboothattendee_card.php
@@ -502,7 +502,15 @@ if (($id || $ref) && $action == 'edit') {
 
 // Part to show record
 if ($object->id > 0 && (empty($action) || ($action != 'edit' && $action != 'create'))) {
-	$res = $object->fetch_optionals();
+	$object->fetch_optionals();
+
+	$moreparam = '';
+	if ($withproject) {
+		$moreparam .= '&withproject=1';
+	}
+	if ($fk_project) {
+		$moreparam .= '&fk_project='.((int) $fk_project);
+	}
 
 	$head = conferenceorboothattendeePrepareHead($object);
 	print dol_get_fiche_head($head, 'card', $langs->trans("ConferenceOrBoothAttendee"), -1, $object->picto);
@@ -544,13 +552,13 @@ if ($object->id > 0 && (empty($action) || ($action != 'edit' && $action != 'crea
 
 	// Object card
 	// ------------------------------------------------------------
-	$linkback = '<a href="'.dol_buildpath('/eventorganization/conferenceorboothattendee_list.php', 1).'?restore_lastsearch_values=1&conforboothid='.$confOrBooth->id .$withProjectUrl.'">'.$langs->trans("BackToList").'</a>';
+	$linkback = '<a href="'.dol_buildpath('/eventorganization/conferenceorboothattendee_list.php', 1).'?restore_lastsearch_values=1'.($confOrBooth->id > 0 ? '&conforboothid='.((int) $confOrBooth->id) : '').$moreparam.'">'.$langs->trans("BackToList").'</a>';
 
 	$morehtmlref = '<div class="refidno">';
 
 	$morehtmlref .= '</div>';
 
-	dol_banner_tab($object, 'ref', $linkback, 1, 'ref', 'ref', $morehtmlref);
+	dol_banner_tab($object, 'ref', $linkback, 1, 'ref', 'ref', $morehtmlref, $moreparam);
 
 	print '<div class="fichecenter">';
 	print '<div class="fichehalfleft">';
diff --git a/htdocs/eventorganization/lib/eventorganization_conferenceorbooth.lib.php b/htdocs/eventorganization/lib/eventorganization_conferenceorbooth.lib.php
index f49bd5e49a0..3951cc25df7 100644
--- a/htdocs/eventorganization/lib/eventorganization_conferenceorbooth.lib.php
+++ b/htdocs/eventorganization/lib/eventorganization_conferenceorbooth.lib.php
@@ -196,7 +196,7 @@ function conferenceorboothattendeePrepareHead($object)
 	$h = 0;
 	$head = array();
 
-	$head[$h][0] = dol_buildpath("/eventorganization/conferenceorboothattendee_card.php", 1).'?id='.$object->id.'&conforboothid='.$object->fk_actioncomm;
+	$head[$h][0] = DOL_URL_ROOT."/eventorganization/conferenceorboothattendee_card.php?id=".((int) $object->id).($object->fk_actioncomm > 0 ? '&conforboothid='.((int) $object->fk_actioncomm) : '').($object->fk_project > 0 ? '&withproject=1&fk_project='.((int) $object->fk_project) : '');
 	$head[$h][1] = $langs->trans("Card");
 	$head[$h][2] = 'card';
 	$h++;