diff --git a/htdocs/core/actions_massactions.inc.php b/htdocs/core/actions_massactions.inc.php
index 37d5b7f05dbf5..5776c85efdb2c 100644
--- a/htdocs/core/actions_massactions.inc.php
+++ b/htdocs/core/actions_massactions.inc.php
@@ -36,6 +36,18 @@
 // $toselect may be defined
 // $diroutputmassaction may be defined
 
+'
+@phan-var-force ?string $permissiontoread
+@phan-var-force ?string $permissiontodelete
+@phan-var-force ?string $permissiontoclose
+@phan-var-force ?string $permissiontoapprove
+@phan-var-force ?int[] $toselect
+@phan-var-force ?string $diroutputmassaction
+@phan-var-force ?string $objectlabel
+@phan-var-force ?string $option
+@phan-var-force ?string $deliveryreceipt
+';
+
 
 // Protection
 if (empty($objectclass) || empty($uploaddir)) {
@@ -47,6 +59,14 @@
 }
 $error = 0;
 
+// Note: list of strings for objectclass could be extended to accepted/expected classes
+'
+@phan-var-force "CommonObject"|"CommandeFournisseur"|"ConferenceOrBoothAttendee"|"Contrat"|"Contact"|"Expedition"|"ExpenseReport"|"Facture"|"FactureFournisseur"|"Fichinter"|"Holiday"|"Partnership"|"Project"|"Propal"|"Societe"|"SupplierProposal" $objectclass
+@phan-var-force string $massaction
+@phan-var-force string $uploaddir
+';
+
+
 // For backward compatibility
 if (!empty($permtoread) && empty($permissiontoread)) {
 	$permissiontoread = $permtoread;
@@ -88,6 +108,7 @@
 	$contactidtosend = array();
 	$attachedfilesThirdpartyObj = array();
 	$oneemailperrecipient = (GETPOSTINT('oneemailperrecipient') ? 1 : 0);
+	$thirdparty = null;
 
 	if (!$error) {
 		$objecttmp = new $objectclass($db);
@@ -108,21 +129,28 @@
 
 		foreach ($toselect as $toselectid) {
 			$objecttmp = new $objectclass($db); // we must create new instance because instance is saved into $listofobjectref array for future use
+			'@phan-var-force CommonObject $objecttmp';
 			$result = $objecttmp->fetch($toselectid);
 			if ($result > 0) {
 				$listofobjectid[$toselectid] = $toselectid;
 				$tmpobjectid = ($objecttmp->fk_soc ? $objecttmp->fk_soc : $objecttmp->socid);
 				if ($objecttmp->element == 'societe') {
+					'@phan-var-force Societe $objecttmp';
 					$tmpobjectid = $objecttmp->id;
 				} elseif ($objecttmp->element == 'contact') {
+					'@phan-var-force Contact $objecttmp';
 					$tmpobjectid = $objecttmp->id;
 				} elseif ($objecttmp->element == 'expensereport') {
+					'@phan-var-force ExpenseReport $objecttmp';
 					$tmpobjectid = $objecttmp->fk_user_author;
 				} elseif ($objecttmp->element == 'partnership' && getDolGlobalString('PARTNERSHIP_IS_MANAGED_FOR') == 'member') {
+					'@phan-var-force Partnership $objecttmp';
 					$tmpobjectid = $objecttmp->fk_member;
 				} elseif ($objecttmp->element == 'holiday') {
+					'@phan-var-force Holiday $objecttmp';
 					$tmpobjectid = $objecttmp->fk_user;
 				} elseif ($objecttmp->element == 'conferenceorboothattendee') {
+					'@phan-var-force ConferenceOrBoothAttendee $objecttmp';
 					$tmpobjectid = $objecttmp->id;
 				}
 				if (empty($tmpobjectid)) {
@@ -130,6 +158,8 @@
 				}
 
 				if ($objectclass == 'Facture') {
+					'@phan-var-force Facture $objecttmp';
+					$tmpobjectid = $objecttmp->id;
 					$tmparraycontact = array();
 					$tmparraycontact = $objecttmp->liste_contact(-1, 'external', 0, 'BILLING');
 					if (is_array($tmparraycontact) && count($tmparraycontact) > 0) {
@@ -138,6 +168,7 @@
 						}
 					}
 				} elseif ($objectclass == 'CommandeFournisseur') {
+					'@phan-var-force CommandeFournisseur $objecttmp';
 					$tmparraycontact = array();
 					$tmparraycontact = $objecttmp->liste_contact(-1, 'external', 0, 'CUSTOMER');
 					if (is_array($tmparraycontact) && count($tmparraycontact) > 0) {
@@ -200,7 +231,7 @@
 				// Recipients are provided into free text
 				$tmparray[] = trim(GETPOST('sendto', 'alphawithlgt'));
 			}
-			if (count($receiver) > 0) {
+			if (count($receiver) > 0 && is_object($thirdparty)) {
 				foreach ($receiver as $key => $val) {
 					// Recipient was provided from combo list
 					if ($val == 'thirdparty') { // Id of third party or user
@@ -1135,6 +1166,11 @@
 // Generate document foreach object according to model linked to object
 // @todo : propose model selection
 if (!$error && $massaction == 'generate_doc' && $permissiontoread) {
+	// Complete with classes that use this massaction
+	<<<'EOPHAN'
+@phan-var-force 'Commande'|'CommandeFournisseur'|'Contrat'|'Expedition'|'ExpenseReport'|'Facture'|'FactureFournisseur'|'Fichinter'|'Project'|'Propal'|'SupplierProposal' $objectclass
+EOPHAN;
+
 	$db->begin();
 	$nbok = 0;
 	foreach ($toselect as $toselectid) {
@@ -1151,7 +1187,7 @@
 				$newlang = $objecttmp->thirdparty->default_lang; // for proposal, order, invoice, ...
 			}
 			if (getDolGlobalInt('MAIN_MULTILANGS') && empty($newlang) && isset($objecttmp->default_lang)) {
-				$newlang = $objecttmp->default_lang; // for thirdparty
+				$newlang = $objecttmp->default_lang; // for thirdparty @phan-suppress-current-line PhanUndeclaredProperty
 			}
 			if (getDolGlobalInt('MAIN_MULTILANGS') && empty($newlang) && empty($objecttmp->thirdparty)) { //load lang from thirdparty
 				$objecttmp->fetch_thirdparty();
@@ -1263,6 +1299,8 @@
 }
 
 if (!$error && ($action == 'updateprice' && $confirm == 'yes') && $permissiontoadd) {
+	'@phan-var-force Product|ProductCustomerPrice $obj';
+	'@phan-var-force Product|ProductCustomerPrice $object';
 	$nbok = 0;
 	$db->begin();
 	if (GETPOSTISSET('pricerate')) {
@@ -1308,9 +1346,10 @@
 }
 
 if (!$error && ($action == 'setsupervisor' && $confirm == 'yes') && $permissiontoadd) {
+	'@phan-var-force User $object';
 	$nbok = 0;
 	$db->begin();
-	$supervisortoset = GETPOST('supervisortoset');
+	$supervisortoset = GETPOSTINT('supervisortoset');
 	if (!empty($supervisortoset)) {
 		foreach ($toselect as $toselectid) {
 			$result = $object->fetch($toselectid);
@@ -1358,7 +1397,7 @@
 				$res = $object->add_contact($usertoaffect, $projectrole, 'internal');
 				if ($res >= 0) {
 					$taskstatic = new Task($db);
-					$task_array = $taskstatic->getTasksArray(0, 0, $object->id, 0, 0);
+					$task_array = $taskstatic->getTasksArray(null, null, $object->id, 0, 0);
 
 					foreach ($task_array as $task) {
 						$tasksToAffect = new Task($db);
@@ -1596,6 +1635,7 @@
 	$db->begin();
 
 	$objecttmp = new $objectclass($db);
+	'@phan-var-force Holiday $objecttmp';
 	$nbok = 0;
 	foreach ($toselect as $toselectid) {
 		$result = $objecttmp->fetch($toselectid);
@@ -1605,7 +1645,7 @@
 				continue;
 			}
 			if ($user->id == $objecttmp->fk_validator) {
-				$objecttmp->oldcopy = dol_clone($objecttmp, 2);
+				$objecttmp->oldcopy = dol_clone($objecttmp, 2);  // @phan-suppress-current-line PhanTypeMismatchProperty
 
 				$objecttmp->date_valid = dol_now();
 				$objecttmp->fk_user_valid = $user->id;
@@ -1712,7 +1752,8 @@
 	}
 }
 
-if (!$error && ($massaction == 'increaseholiday' || ($action == 'increaseholiday' && $confirm == 'yes')) && $permissiontoapprove) {
+if (!$error && ($massaction == 'increaseholiday' || ($action == 'increaseholiday' && $confirm == 'yes')) && $permissiontoapprove && is_array($toselect)) {
+	'@phan-var-force Holiday $holiday';  // Supposing that $holiday is set, it is needed.
 	$db->begin();
 	$objecttmp = new $objectclass($db);
 	$nbok = 0;
@@ -1780,6 +1821,7 @@
 		if (getDolGlobalString('PROJECT_TASK_ADDON') && is_readable(DOL_DOCUMENT_ROOT . "/core/modules/project/task/" . getDolGlobalString('PROJECT_TASK_ADDON') . ".php")) {
 			require_once DOL_DOCUMENT_ROOT . "/core/modules/project/task/" . getDolGlobalString('PROJECT_TASK_ADDON') . '.php';
 			$modTask = new $obj();
+			'@phan-var-force ModeleNumRefTask $modTask';
 			$defaultref = $modTask->getNextValue(0, $clone_task);
 		}