diff --git a/admin_domains.php b/admin_domains.php
index e4170e8b..fc88f711 100644
--- a/admin_domains.php
+++ b/admin_domains.php
@@ -640,8 +640,8 @@ if ($page == 'domains' || $page == 'overview') {
 
 			// update customer/admin counters
 			\Froxlor\User::updateCounters(false);
-			\Froxlor\System\Cronjob::inserttask('1');
-			\Froxlor\System\Cronjob::inserttask('4');
+			\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::REBUILD_VHOST);
+			\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::REBUILD_DNS);
 
 			$result_str = $result['imported'] . ' / ' . $result['all'] . (! empty($result['note']) ? ' (' . $result['note'] . ')' : '');
 			\Froxlor\UI\Response::standard_success('domain_import_successfully', $result_str, array(
diff --git a/admin_settings.php b/admin_settings.php
index 4e9aba21..162fe4d3 100644
--- a/admin_settings.php
+++ b/admin_settings.php
@@ -66,11 +66,11 @@ if ($page == 'overview' && $userinfo['change_serversettings'] == '1') {
 			'page' => $page
 		), $_part, $settings_all, $settings_part, $only_enabledisable)) {
 			$log->logAction(\Froxlor\FroxlorLogger::ADM_ACTION, LOG_INFO, "rebuild configfiles due to changed setting");
-			\Froxlor\System\Cronjob::inserttask('1');
+			\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::REBUILD_VHOST);
 			// Using nameserver, insert a task which rebuilds the server config
-			\Froxlor\System\Cronjob::inserttask('4');
+			\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::REBUILD_DNS);
 			// cron.d file
-			\Froxlor\System\Cronjob::inserttask('99');
+			\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::REBUILD_CRON);
 
 			\Froxlor\UI\Response::standard_success('settingssaved', '', array(
 				'filename' => $filename,
@@ -146,12 +146,12 @@ if ($page == 'overview' && $userinfo['change_serversettings'] == '1') {
 	if (isset($_POST['send']) && $_POST['send'] == 'send') {
 
 		$log->logAction(\Froxlor\FroxlorLogger::ADM_ACTION, LOG_INFO, "rebuild configfiles");
-		\Froxlor\System\Cronjob::inserttask('1');
-		\Froxlor\System\Cronjob::inserttask('10');
+		\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::REBUILD_VHOST);
+		\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::CREATE_QUOTA);
 		// Using nameserver, insert a task which rebuilds the server config
-		\Froxlor\System\Cronjob::inserttask('4');
+		\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::REBUILD_DNS);
 		// cron.d file
-		\Froxlor\System\Cronjob::inserttask('99');
+		\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::REBUILD_CRON);
 
 		\Froxlor\UI\Response::standard_success('rebuildingconfigs', '', array(
 			'filename' => 'admin_index.php'
diff --git a/admin_updates.php b/admin_updates.php
index 2b0e3420..9f6357df 100644
--- a/admin_updates.php
+++ b/admin_updates.php
@@ -65,7 +65,7 @@ if ($page == 'overview') {
 				eval("echo \"" . \Froxlor\UI\Template::getTemplate('update/update_end') . "\";");
 
 				\Froxlor\User::updateCounters();
-				\Froxlor\System\Cronjob::inserttask('1');
+				\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::REBUILD_VHOST);
 				@chmod(\Froxlor\Froxlor::getInstallDir() . '/lib/userdata.inc.php', 0440);
 
 				$successful_update = true;
diff --git a/lib/Froxlor/Api/Commands/Certificates.php b/lib/Froxlor/Api/Commands/Certificates.php
index 69ffc718..a611eedf 100644
--- a/lib/Froxlor/Api/Commands/Certificates.php
+++ b/lib/Froxlor/Api/Commands/Certificates.php
@@ -323,7 +323,7 @@ class Certificates extends \Froxlor\Api\ApiCommand implements \Froxlor\Api\Resou
 			));
 			// trigger removing of certificate from acme.sh if let's encrypt
 			if ($chk['letsencrypt'] == '1') {
-				\Froxlor\System\Cronjob::inserttask('12', $chk['domain']);
+				\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::DELETE_DOMAIN_SSL, $chk['domain']);
 			}
 			$this->logger()->logAction($this->isAdmin() ? \Froxlor\FroxlorLogger::ADM_ACTION : \Froxlor\FroxlorLogger::USR_ACTION, LOG_INFO, "[API] removed ssl-certificate for '" . $chk['domain'] . "'");
 			return $this->response(200, "successful", $result);
@@ -421,7 +421,7 @@ class Certificates extends \Froxlor\Api\ApiCommand implements \Froxlor\Api\Resou
 		);
 		Database::pexecute($stmt, $params, true, true);
 		// insert task to re-generate webserver-configs (#1260)
-		\Froxlor\System\Cronjob::inserttask('1');
+		\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::REBUILD_VHOST);
 		return true;
 	}
 }
diff --git a/lib/Froxlor/Api/Commands/Cronjobs.php b/lib/Froxlor/Api/Commands/Cronjobs.php
index d6bd7889..34c0f218 100644
--- a/lib/Froxlor/Api/Commands/Cronjobs.php
+++ b/lib/Froxlor/Api/Commands/Cronjobs.php
@@ -114,7 +114,7 @@ class Cronjobs extends \Froxlor\Api\ApiCommand implements \Froxlor\Api\ResourceE
 			), true, true);
 
 			// insert task to re-generate the cron.d-file
-			\Froxlor\System\Cronjob::inserttask('99');
+			\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::REBUILD_CRON);
 			$this->logger()->logAction(\Froxlor\FroxlorLogger::ADM_ACTION, LOG_INFO, "[API] cronjob with description '" . $result['module'] . '/' . $result['cronfile'] . "' has been updated by '" . $this->getUserDetail('loginname') . "'");
 			$result = $this->apiCall('Cronjobs.get', array(
 				'id' => $id
diff --git a/lib/Froxlor/Api/Commands/CustomerBackups.php b/lib/Froxlor/Api/Commands/CustomerBackups.php
index 84941cec..f899b6ca 100644
--- a/lib/Froxlor/Api/Commands/CustomerBackups.php
+++ b/lib/Froxlor/Api/Commands/CustomerBackups.php
@@ -108,7 +108,7 @@ class CustomerBackups extends \Froxlor\Api\ApiCommand implements \Froxlor\Api\Re
 			'backup_web' => $backup_web
 		);
 		// schedule backup job
-		\Froxlor\System\Cronjob::inserttask('20', $task_data);
+		\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::CREATE_CUSTOMER_BACKUP, $task_data);
 
 		$this->logger()->logAction($this->isAdmin() ? \Froxlor\FroxlorLogger::ADM_ACTION : \Froxlor\FroxlorLogger::USR_ACTION, LOG_NOTICE, "[API] added customer-backup job for '" . $customer['loginname'] . "'. Target directory: " . $userpath);
 		return $this->response(200, "successful", $task_data);
diff --git a/lib/Froxlor/Api/Commands/Customers.php b/lib/Froxlor/Api/Commands/Customers.php
index e89031c3..b1dd1034 100644
--- a/lib/Froxlor/Api/Commands/Customers.php
+++ b/lib/Froxlor/Api/Commands/Customers.php
@@ -645,10 +645,10 @@ class Customers extends \Froxlor\Api\ApiCommand implements \Froxlor\Api\Resource
 					unset($ins_data);
 
 					// insert task to create homedir etc.
-					\Froxlor\System\Cronjob::inserttask('2', $loginname, $guid, $guid, $store_defaultindex);
+					\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::CREATE_HOME, $loginname, $guid, $guid, $store_defaultindex);
 
 					// Using filesystem - quota, insert a task which cleans the filesystem - quota
-					\Froxlor\System\Cronjob::inserttask('10');
+					\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::CREATE_QUOTA);
 
 					// Add htpasswd for the stats-pages
 					$htpasswdPassword = \Froxlor\System\Crypt::makeCryptPassword($password, true);
@@ -674,7 +674,7 @@ class Customers extends \Froxlor\Api\ApiCommand implements \Froxlor\Api\Resource
 					$this->logger()->logAction(\Froxlor\FroxlorLogger::ADM_ACTION, LOG_NOTICE, "[API] automatically added " . $stats_folder . " htpasswd for user '" . $loginname . "'");
 					Database::pexecute($ins_stmt, $ins_data, true, true);
 
-					\Froxlor\System\Cronjob::inserttask('1');
+					\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::REBUILD_VHOST);
 
 					// add default FTP-User
 					// also, add froxlor-local user to ftp-group (if exists!) to
@@ -739,7 +739,7 @@ class Customers extends \Froxlor\Api\ApiCommand implements \Froxlor\Api\Resource
 								'customerid' => $customerid
 							), true, true);
 							$this->logger()->logAction(\Froxlor\FroxlorLogger::ADM_ACTION, LOG_NOTICE, "[API] automatically added standardsubdomain for user '" . $loginname . "'");
-							\Froxlor\System\Cronjob::inserttask('1');
+							\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::REBUILD_VHOST);
 						}
 					}
 
@@ -1088,7 +1088,7 @@ class Customers extends \Froxlor\Api\ApiCommand implements \Froxlor\Api\Resource
 						'customerid' => $result['customerid']
 					), true, true);
 					$this->logger()->logAction(\Froxlor\FroxlorLogger::ADM_ACTION, LOG_NOTICE, "[API] automatically added standardsubdomain for user '" . $result['loginname'] . "'");
-					\Froxlor\System\Cronjob::inserttask('1');
+					\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::REBUILD_VHOST);
 				}
 			}
 
@@ -1102,11 +1102,11 @@ class Customers extends \Froxlor\Api\ApiCommand implements \Froxlor\Api\Resource
 					$this->logger()->logAction(\Froxlor\FroxlorLogger::ADM_ACTION, LOG_ERR, "[API] Unable to delete standard-subdomain: " . $e->getMessage());
 				}
 				$this->logger()->logAction(\Froxlor\FroxlorLogger::ADM_ACTION, LOG_NOTICE, "[API] automatically deleted standardsubdomain for user '" . $result['loginname'] . "'");
-				\Froxlor\System\Cronjob::inserttask('1');
+				\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::REBUILD_VHOST);
 			}
 
 			if ($phpenabled != $result['phpenabled'] || $perlenabled != $result['perlenabled'] || $email != $result['email']) {
-				\Froxlor\System\Cronjob::inserttask('1');
+				\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::REBUILD_VHOST);
 			}
 
 			// activate/deactivate customer services
@@ -1192,7 +1192,7 @@ class Customers extends \Froxlor\Api\ApiCommand implements \Froxlor\Api\Resource
 				), true, true);
 
 				$this->logger()->logAction(\Froxlor\FroxlorLogger::ADM_ACTION, LOG_INFO, "[API] " . ($deactivated ? 'deactivated' : 'reactivated') . " user '" . $result['loginname'] . "'");
-				\Froxlor\System\Cronjob::inserttask('1');
+				\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::REBUILD_VHOST);
 			}
 
 			// Disable or enable POP3 Login for customers Mail Accounts
@@ -1304,7 +1304,7 @@ class Customers extends \Froxlor\Api\ApiCommand implements \Froxlor\Api\Resource
 
 		if ($this->isAdmin()) {
 			// Using filesystem - quota, insert a task which cleans the filesystem - quota
-			\Froxlor\System\Cronjob::inserttask('10');
+			\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::CREATE_QUOTA);
 
 			$admin_update_query = "UPDATE `" . TABLE_PANEL_ADMINS . "` SET `customers_used` = `customers_used` ";
 
@@ -1512,9 +1512,9 @@ class Customers extends \Froxlor\Api\ApiCommand implements \Froxlor\Api\Resource
 					'did' => $row['id']
 				), true, true);
 				// remove domains DNS from powerDNS if used, #581
-				\Froxlor\System\Cronjob::inserttask('11', $row['domain']);
+				\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::DELETE_DOMAIN_PDNS, $row['domain']);
 				// remove domain from acme.sh / lets encrypt if used
-				\Froxlor\System\Cronjob::inserttask('12', $row['domain']);
+				\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::DELETE_DOMAIN_SSL, $row['domain']);
 			}
 			// remove customer domains
 			$stmt = Database::prepare("DELETE FROM `" . TABLE_PANEL_DOMAINS . "` WHERE `customerid` = :id");
@@ -1643,18 +1643,18 @@ class Customers extends \Froxlor\Api\ApiCommand implements \Froxlor\Api\Resource
 			}
 
 			// rebuild configs
-			\Froxlor\System\Cronjob::inserttask('1');
+			\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::REBUILD_VHOST);
 
 			// Using nameserver, insert a task which rebuilds the server config
-			\Froxlor\System\Cronjob::inserttask('4');
+			\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::REBUILD_DNS);
 
 			if ($delete_userfiles == 1) {
 				// insert task to remove the customers files from the filesystem
-				\Froxlor\System\Cronjob::inserttask('6', $result['loginname']);
+				\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::DELETE_CUSTOMER_FILES, $result['loginname']);
 			}
 
 			// Using filesystem - quota, insert a task which cleans the filesystem - quota
-			\Froxlor\System\Cronjob::inserttask('10');
+			\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::CREATE_QUOTA);
 
 			$this->logger()->logAction(\Froxlor\FroxlorLogger::ADM_ACTION, LOG_WARNING, "[API] deleted customer '" . $result['loginname'] . "'");
 			return $this->response(200, "successful", $result);
diff --git a/lib/Froxlor/Api/Commands/DirOptions.php b/lib/Froxlor/Api/Commands/DirOptions.php
index fc54f0cb..d5c0c010 100644
--- a/lib/Froxlor/Api/Commands/DirOptions.php
+++ b/lib/Froxlor/Api/Commands/DirOptions.php
@@ -123,7 +123,7 @@ class DirOptions extends \Froxlor\Api\ApiCommand implements \Froxlor\Api\Resourc
 		Database::pexecute($stmt, $params, true, true);
 		$id = Database::lastInsertId();
 		$this->logger()->logAction($this->isAdmin() ? \Froxlor\FroxlorLogger::ADM_ACTION : \Froxlor\FroxlorLogger::USR_ACTION, LOG_INFO, "[API] added directory-option for '" . $userpath . "'");
-		\Froxlor\System\Cronjob::inserttask('1');
+		\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::REBUILD_VHOST);
 
 		$result = $this->apiCall('DirOptions.get', array(
 			'id' => $id
@@ -248,7 +248,7 @@ class DirOptions extends \Froxlor\Api\ApiCommand implements \Froxlor\Api\Resourc
 		}
 
 		if (($options_indexes != $result['options_indexes']) || ($error404path != $result['error404path']) || ($error403path != $result['error403path']) || ($error500path != $result['error500path']) || ($options_cgi != $result['options_cgi'])) {
-			\Froxlor\System\Cronjob::inserttask('1');
+			\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::REBUILD_VHOST);
 			$stmt = Database::prepare("
 				UPDATE `" . TABLE_PANEL_HTACCESS . "`
 				SET `options_indexes` = :options_indexes,
@@ -413,7 +413,7 @@ class DirOptions extends \Froxlor\Api\ApiCommand implements \Froxlor\Api\Resourc
 			"id" => $id
 		), true, true);
 		$this->logger()->logAction($this->isAdmin() ? \Froxlor\FroxlorLogger::ADM_ACTION : \Froxlor\FroxlorLogger::USR_ACTION, LOG_INFO, "[API] deleted directory-option for '" . str_replace($customer_data['documentroot'], '/', $result['path']) . "'");
-		\Froxlor\System\Cronjob::inserttask('1');
+		\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::REBUILD_VHOST);
 		return $this->response(200, "successful", $result);
 	}
 
diff --git a/lib/Froxlor/Api/Commands/DirProtections.php b/lib/Froxlor/Api/Commands/DirProtections.php
index 241592d2..8137b93e 100644
--- a/lib/Froxlor/Api/Commands/DirProtections.php
+++ b/lib/Froxlor/Api/Commands/DirProtections.php
@@ -106,7 +106,7 @@ class DirProtections extends \Froxlor\Api\ApiCommand implements \Froxlor\Api\Res
 		Database::pexecute($stmt, $params, true, true);
 		$id = Database::lastInsertId();
 		$this->logger()->logAction($this->isAdmin() ? \Froxlor\FroxlorLogger::ADM_ACTION : \Froxlor\FroxlorLogger::USR_ACTION, LOG_INFO, "[API] added directory-protection for '" . $username . " (" . $path . ")'");
-		\Froxlor\System\Cronjob::inserttask('1');
+		\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::REBUILD_VHOST);
 
 		$result = $this->apiCall('DirProtections.get', array(
 			'id' => $id
@@ -251,7 +251,7 @@ class DirProtections extends \Froxlor\Api\ApiCommand implements \Froxlor\Api\Res
 				UPDATE `" . TABLE_PANEL_HTPASSWDS . "` SET " . $upd_query . " WHERE `id` = :id AND `customerid`= :cid
 			");
 			Database::pexecute($upd_stmt, $upd_params, true, true);
-			\Froxlor\System\Cronjob::inserttask('1');
+			\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::REBUILD_VHOST);
 		}
 
 		$this->logger()->logAction($this->isAdmin() ? \Froxlor\FroxlorLogger::ADM_ACTION : \Froxlor\FroxlorLogger::USR_ACTION, LOG_INFO, "[API] updated directory-protection '" . $result['username'] . " (" . $result['path'] . ")'");
@@ -385,7 +385,7 @@ class DirProtections extends \Froxlor\Api\ApiCommand implements \Froxlor\Api\Res
 		));
 
 		$this->logger()->logAction($this->isAdmin() ? \Froxlor\FroxlorLogger::ADM_ACTION : \Froxlor\FroxlorLogger::USR_ACTION, LOG_INFO, "[API] deleted htpasswd for '" . $result['username'] . " (" . $result['path'] . ")'");
-		\Froxlor\System\Cronjob::inserttask('1');
+		\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::REBUILD_VHOST);
 		return $this->response(200, "successful", $result);
 	}
 }
diff --git a/lib/Froxlor/Api/Commands/DomainZones.php b/lib/Froxlor/Api/Commands/DomainZones.php
index a51e59e0..7c0b385b 100644
--- a/lib/Froxlor/Api/Commands/DomainZones.php
+++ b/lib/Froxlor/Api/Commands/DomainZones.php
@@ -336,7 +336,7 @@ class DomainZones extends \Froxlor\Api\ApiCommand implements \Froxlor\Api\Resour
 			$dom_entries[] = $new_entry;
 
 			// re-generate bind configs
-			\Froxlor\System\Cronjob::inserttask('4');
+			\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::REBUILD_DNS);
 
 			$result = $this->apiCall('DomainZones.get', array(
 				'id' => $id
@@ -542,7 +542,7 @@ class DomainZones extends \Froxlor\Api\ApiCommand implements \Froxlor\Api\Resour
 		), true, true);
 		if ($del_stmt->rowCount() > 0) {
 			// re-generate bind configs
-			\Froxlor\System\Cronjob::inserttask('4');
+			\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::REBUILD_DNS);
 			return $this->response(200, "successful", true);
 		}
 		return $this->response(304, "successful", true);
diff --git a/lib/Froxlor/Api/Commands/Domains.php b/lib/Froxlor/Api/Commands/Domains.php
index 5718808b..3113f528 100644
--- a/lib/Froxlor/Api/Commands/Domains.php
+++ b/lib/Froxlor/Api/Commands/Domains.php
@@ -857,9 +857,9 @@ class Domains extends \Froxlor\Api\ApiCommand implements \Froxlor\Api\ResourceEn
 
 					\Froxlor\Domain\Domain::triggerLetsEncryptCSRForAliasDestinationDomain($aliasdomain, $this->logger());
 
-					\Froxlor\System\Cronjob::inserttask('1');
+					\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::REBUILD_VHOST);
 					// Using nameserver, insert a task which rebuilds the server config
-					\Froxlor\System\Cronjob::inserttask('4');
+					\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::REBUILD_DNS);
 
 					$this->logger()->logAction(\Froxlor\FroxlorLogger::ADM_ACTION, LOG_WARNING, "[API] added domain '" . $domain . "'");
 
@@ -1465,7 +1465,7 @@ class Domains extends \Froxlor\Api\ApiCommand implements \Froxlor\Api\ResourceEn
 			$iswildcarddomain = ($serveraliasoption == '0') ? '1' : '0';
 
 			if ($documentroot != $result['documentroot'] || $ssl_redirect != $result['ssl_redirect'] || $wwwserveralias != $result['wwwserveralias'] || $iswildcarddomain != $result['iswildcarddomain'] || $phpenabled != $result['phpenabled'] || $openbasedir != $result['openbasedir'] || $phpsettingid != $result['phpsettingid'] || $mod_fcgid_starter != $result['mod_fcgid_starter'] || $mod_fcgid_maxrequests != $result['mod_fcgid_maxrequests'] || $specialsettings != $result['specialsettings'] || $ssl_specialsettings != $result['ssl_specialsettings'] || $notryfiles != $result['notryfiles'] || $writeaccesslog != $result['writeaccesslog'] || $writeerrorlog != $result['writeerrorlog'] || $aliasdomain != $result['aliasdomain'] || $issubof != $result['ismainbutsubto'] || $email_only != $result['email_only'] || ($speciallogfile != $result['speciallogfile'] && $speciallogverified == '1') || $letsencrypt != $result['letsencrypt'] || $http2 != $result['http2'] || $hsts_maxage != $result['hsts'] || $hsts_sub != $result['hsts_sub'] || $hsts_preload != $result['hsts_preload'] || $ocsp_stapling != $result['ocsp_stapling']) {
-				\Froxlor\System\Cronjob::inserttask('1');
+				\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::REBUILD_VHOST);
 			}
 
 			if ($speciallogfile != $result['speciallogfile'] && $speciallogverified != '1') {
@@ -1473,11 +1473,11 @@ class Domains extends \Froxlor\Api\ApiCommand implements \Froxlor\Api\ResourceEn
 			}
 
 			if ($isbinddomain != $result['isbinddomain'] || $zonefile != $result['zonefile'] || $dkim != $result['dkim'] || $isemaildomain != $result['isemaildomain']) {
-				\Froxlor\System\Cronjob::inserttask('4');
+				\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::REBUILD_DNS);
 			}
 			// check whether nameserver has been disabled, #581
 			if ($isbinddomain != $result['isbinddomain'] && $isbinddomain == 0) {
-				\Froxlor\System\Cronjob::inserttask('11', $result['domain']);
+				\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::DELETE_DOMAIN_PDNS, $result['domain']);
 			}
 
 			if ($isemaildomain == '0' && $result['isemaildomain'] == '1') {
@@ -1506,7 +1506,7 @@ class Domains extends \Froxlor\Api\ApiCommand implements \Froxlor\Api\ResourceEn
 					'id' => $id
 				), true, true);
 				// remove domain from acme.sh / lets encrypt if used
-				\Froxlor\System\Cronjob::inserttask('12', $result['domain']);
+				\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::DELETE_DOMAIN_SSL, $result['domain']);
 			}
 
 			$updatechildren = '';
@@ -1984,16 +1984,16 @@ class Domains extends \Froxlor\Api\ApiCommand implements \Froxlor\Api\ResourceEn
 			\Froxlor\Domain\Domain::triggerLetsEncryptCSRForAliasDestinationDomain($result['aliasdomain'], $this->logger());
 
 			// remove domains DNS from powerDNS if used, #581
-			\Froxlor\System\Cronjob::inserttask('11', $result['domain']);
+			\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::DELETE_DOMAIN_PDNS, $result['domain']);
 
 			// remove domain from acme.sh / lets encrypt if used
-			\Froxlor\System\Cronjob::inserttask('12', $result['domain']);
+			\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::DELETE_DOMAIN_SSL, $result['domain']);
 
 			$this->logger()->logAction(\Froxlor\FroxlorLogger::ADM_ACTION, LOG_INFO, "[API] deleted domain/subdomains (#" . $result['id'] . ")");
 			\Froxlor\User::updateCounters();
-			\Froxlor\System\Cronjob::inserttask('1');
+			\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::REBUILD_VHOST);
 			// Using nameserver, insert a task which rebuilds the server config
-			\Froxlor\System\Cronjob::inserttask('4');
+			\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::REBUILD_DNS);
 			return $this->response(200, "successful", $result);
 		}
 		throw new \Exception("Not allowed to execute given command.", 403);
diff --git a/lib/Froxlor/Api/Commands/EmailAccounts.php b/lib/Froxlor/Api/Commands/EmailAccounts.php
index 34b9d06b..9ee1d16c 100644
--- a/lib/Froxlor/Api/Commands/EmailAccounts.php
+++ b/lib/Froxlor/Api/Commands/EmailAccounts.php
@@ -499,7 +499,7 @@ class EmailAccounts extends \Froxlor\Api\ApiCommand implements \Froxlor\Api\Reso
 		}
 
 		if ($delete_userfiles) {
-			\Froxlor\System\Cronjob::inserttask('7', $customer['loginname'], $result['email_full']);
+			\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::DELETE_EMAIL_DATA, $customer['loginname'], $result['email_full']);
 		}
 
 		// decrease usage for customer
diff --git a/lib/Froxlor/Api/Commands/FpmDaemons.php b/lib/Froxlor/Api/Commands/FpmDaemons.php
index 36fed4e0..b443798b 100644
--- a/lib/Froxlor/Api/Commands/FpmDaemons.php
+++ b/lib/Froxlor/Api/Commands/FpmDaemons.php
@@ -229,7 +229,7 @@ class FpmDaemons extends \Froxlor\Api\ApiCommand implements \Froxlor\Api\Resourc
 			Database::pexecute($ins_stmt, $ins_data);
 			$id = Database::lastInsertId();
 
-			\Froxlor\System\Cronjob::inserttask('1');
+			\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::REBUILD_VHOST);
 			$this->logger()->logAction(\Froxlor\FroxlorLogger::ADM_ACTION, LOG_INFO, "[API] fpm-daemon with description '" . $description . "' has been created by '" . $this->getUserDetail('loginname') . "'");
 			$result = $this->apiCall('FpmDaemons.get', array(
 				'id' => $id
@@ -351,7 +351,7 @@ class FpmDaemons extends \Froxlor\Api\ApiCommand implements \Froxlor\Api\Resourc
 			);
 			Database::pexecute($upd_stmt, $upd_data, true, true);
 
-			\Froxlor\System\Cronjob::inserttask('1');
+			\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::REBUILD_VHOST);
 			$this->logger()->logAction(\Froxlor\FroxlorLogger::ADM_ACTION, LOG_INFO, "[API] fpm-daemon with description '" . $description . "' has been updated by '" . $this->getUserDetail('loginname') . "'");
 			$result = $this->apiCall('FpmDaemons.get', array(
 				'id' => $id
@@ -400,7 +400,7 @@ class FpmDaemons extends \Froxlor\Api\ApiCommand implements \Froxlor\Api\Resourc
 				'id' => $id
 			), true, true);
 
-			\Froxlor\System\Cronjob::inserttask('1');
+			\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::REBUILD_VHOST);
 			$this->logger()->logAction(\Froxlor\FroxlorLogger::ADM_ACTION, LOG_INFO, "[API] fpm-daemon setting '" . $result['description'] . "' has been deleted by '" . $this->getUserDetail('loginname') . "'");
 			return $this->response(200, "successful", $result);
 		}
diff --git a/lib/Froxlor/Api/Commands/Froxlor.php b/lib/Froxlor/Api/Commands/Froxlor.php
index 78c772c9..7aecb886 100644
--- a/lib/Froxlor/Api/Commands/Froxlor.php
+++ b/lib/Froxlor/Api/Commands/Froxlor.php
@@ -123,12 +123,12 @@ class Froxlor extends \Froxlor\Api\ApiCommand
 			$this->logger()->logAction(\Froxlor\FroxlorLogger::ADM_ACTION, LOG_NOTICE, "User " . $this->getUserDetail('loginname') . " imported settings");
 			try {
 				\Froxlor\SImExporter::import($json_str);
-				\Froxlor\System\Cronjob::inserttask('1');
-				\Froxlor\System\Cronjob::inserttask('10');
+				\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::REBUILD_VHOST);
+				\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::CREATE_QUOTA);
 				// Using nameserver, insert a task which rebuilds the server config
-				\Froxlor\System\Cronjob::inserttask('4');
+				\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::REBUILD_DNS);
 				// cron.d file
-				\Froxlor\System\Cronjob::inserttask('99');
+				\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::REBUILD_CRON);
 				return $this->response(200, "successful", true);
 			} catch (\Exception $e) {
 				throw new \Exception($e->getMessage(), 406);
diff --git a/lib/Froxlor/Api/Commands/Ftps.php b/lib/Froxlor/Api/Commands/Ftps.php
index 9d7664b4..5b05cf13 100644
--- a/lib/Froxlor/Api/Commands/Ftps.php
+++ b/lib/Froxlor/Api/Commands/Ftps.php
@@ -234,7 +234,7 @@ class Ftps extends \Froxlor\Api\ApiCommand implements \Froxlor\Api\ResourceEntit
 				}
 
 				$this->logger()->logAction($this->isAdmin() ? \Froxlor\FroxlorLogger::ADM_ACTION : \Froxlor\FroxlorLogger::USR_ACTION, LOG_INFO, "[API] added ftp-account '" . $username . " (" . $path . ")'");
-				\Froxlor\System\Cronjob::inserttask(5);
+				\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::CREATE_FTP);
 
 				if ($sendinfomail == 1) {
 					$replace_arr = array(
@@ -450,7 +450,7 @@ class Ftps extends \Froxlor\Api\ApiCommand implements \Froxlor\Api\ResourceEntit
 		}
 		// it's the task for "new ftp" but that will
 		// create all directories and correct their permissions
-		\Froxlor\System\Cronjob::inserttask(5);
+		\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::CREATE_FTP);
 
 		$stmt = Database::prepare("
 			UPDATE `" . TABLE_FTP_USERS . "`
@@ -628,11 +628,11 @@ class Ftps extends \Froxlor\Api\ApiCommand implements \Froxlor\Api\ResourceEntit
 
 		// refs #293
 		if ($delete_userfiles == 1) {
-			\Froxlor\System\Cronjob::inserttask('8', $customer_data['loginname'], $result['homedir']);
+			\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::DELETE_FTP_DATA, $customer_data['loginname'], $result['homedir']);
 		} else {
 			if (Settings::Get('system.nssextrausers') == 1) {
 				// this is used so that the libnss-extrausers cron is fired
-				\Froxlor\System\Cronjob::inserttask(5);
+				\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::CREATE_FTP);
 			}
 		}
 
diff --git a/lib/Froxlor/Api/Commands/IpsAndPorts.php b/lib/Froxlor/Api/Commands/IpsAndPorts.php
index 4f8fd1e4..71d836fb 100644
--- a/lib/Froxlor/Api/Commands/IpsAndPorts.php
+++ b/lib/Froxlor/Api/Commands/IpsAndPorts.php
@@ -298,9 +298,9 @@ class IpsAndPorts extends \Froxlor\Api\ApiCommand implements \Froxlor\Api\Resour
 			Database::pexecute($ins_stmt, $ins_data);
 			$ins_data['id'] = Database::lastInsertId();
 
-			\Froxlor\System\Cronjob::inserttask('1');
+			\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::REBUILD_VHOST);
 			// Using nameserver, insert a task which rebuilds the server config
-			\Froxlor\System\Cronjob::inserttask('4');
+			\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::REBUILD_DNS);
 
 			if (filter_var($ip, FILTER_VALIDATE_IP, FILTER_FLAG_IPV6)) {
 				$ip = '[' . $ip . ']';
@@ -511,9 +511,9 @@ class IpsAndPorts extends \Froxlor\Api\ApiCommand implements \Froxlor\Api\Resour
 				);
 				Database::pexecute($upd_stmt, $upd_data);
 
-				\Froxlor\System\Cronjob::inserttask('1');
+				\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::REBUILD_VHOST);
 				// Using nameserver, insert a task which rebuilds the server config
-				\Froxlor\System\Cronjob::inserttask('4');
+				\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::REBUILD_DNS);
 
 				$this->logger()->logAction(\Froxlor\FroxlorLogger::ADM_ACTION, LOG_WARNING, "[API] changed IP/port from '" . $result['ip'] . ":" . $result['port'] . "' to '" . $ip . ":" . $port . "'");
 
@@ -584,9 +584,9 @@ class IpsAndPorts extends \Froxlor\Api\ApiCommand implements \Froxlor\Api\Resour
 							'id' => $id
 						), true, true);
 
-						\Froxlor\System\Cronjob::inserttask('1');
+						\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::REBUILD_VHOST);
 						// Using nameserver, insert a task which rebuilds the server config
-						\Froxlor\System\Cronjob::inserttask('4');
+						\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::REBUILD_DNS);
 
 						$this->logger()->logAction(\Froxlor\FroxlorLogger::ADM_ACTION, LOG_WARNING, "[API] deleted IP/port '" . $result['ip'] . ":" . $result['port'] . "'");
 						return $this->response(200, "successful", $result);
diff --git a/lib/Froxlor/Api/Commands/PhpSettings.php b/lib/Froxlor/Api/Commands/PhpSettings.php
index 6689241a..ae59726f 100644
--- a/lib/Froxlor/Api/Commands/PhpSettings.php
+++ b/lib/Froxlor/Api/Commands/PhpSettings.php
@@ -364,7 +364,7 @@ class PhpSettings extends \Froxlor\Api\ApiCommand implements \Froxlor\Api\Resour
 			Database::pexecute($ins_stmt, $ins_data, true, true);
 			$ins_data['id'] = Database::lastInsertId();
 
-			\Froxlor\System\Cronjob::inserttask('1');
+			\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::REBUILD_VHOST);
 			$this->logger()->logAction(\Froxlor\FroxlorLogger::ADM_ACTION, LOG_INFO, "[API] php setting with description '" . $description . "' has been created by '" . $this->getUserDetail('loginname') . "'");
 
 			$result = $this->apiCall('PhpSettings.get', array(
@@ -565,7 +565,7 @@ class PhpSettings extends \Froxlor\Api\ApiCommand implements \Froxlor\Api\Resour
 			);
 			Database::pexecute($upd_stmt, $upd_data, true, true);
 
-			\Froxlor\System\Cronjob::inserttask('1');
+			\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::REBUILD_VHOST);
 			$this->logger()->logAction(\Froxlor\FroxlorLogger::ADM_ACTION, LOG_INFO, "[API] php setting with description '" . $description . "' has been updated by '" . $this->getUserDetail('loginname') . "'");
 
 			$result = $this->apiCall('PhpSettings.get', array(
@@ -622,7 +622,7 @@ class PhpSettings extends \Froxlor\Api\ApiCommand implements \Froxlor\Api\Resour
 				'id' => $id
 			), true, true);
 
-			\Froxlor\System\Cronjob::inserttask('1');
+			\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::REBUILD_VHOST);
 			$this->logger()->logAction(\Froxlor\FroxlorLogger::ADM_ACTION, LOG_INFO, "[API] php setting '" . $result['description'] . "' has been deleted by '" . $this->getUserDetail('loginname') . "'");
 			return $this->response(200, "successful", $result);
 		}
diff --git a/lib/Froxlor/Api/Commands/SubDomains.php b/lib/Froxlor/Api/Commands/SubDomains.php
index c3a0a322..16717ea5 100644
--- a/lib/Froxlor/Api/Commands/SubDomains.php
+++ b/lib/Froxlor/Api/Commands/SubDomains.php
@@ -359,9 +359,9 @@ class SubDomains extends \Froxlor\Api\ApiCommand implements \Froxlor\Api\Resourc
 				\Froxlor\Domain\Domain::addRedirectToDomain($subdomain_id, $redirectcode);
 			}
 
-			\Froxlor\System\Cronjob::inserttask('1');
+			\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::REBUILD_VHOST);
 			// Using nameserver, insert a task which rebuilds the server config
-			\Froxlor\System\Cronjob::inserttask('4');
+			\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::REBUILD_DNS);
 
 			Customers::increaseUsage($customer['customerid'], 'subdomains_used');
 
@@ -733,11 +733,11 @@ class SubDomains extends \Froxlor\Api\ApiCommand implements \Froxlor\Api\Resourc
 					'id' => $id
 				), true, true);
 				// remove domain from acme.sh / lets encrypt if used
-				\Froxlor\System\Cronjob::inserttask('12', $result['domain']);
+				\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::DELETE_DOMAIN_SSL, $result['domain']);
 			}
 
-			\Froxlor\System\Cronjob::inserttask('1');
-			\Froxlor\System\Cronjob::inserttask('4');
+			\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::REBUILD_VHOST);
+			\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::REBUILD_DNS);
 			$idna_convert = new \Froxlor\Idna\IdnaWrapper();
 			$this->logger()->logAction($this->isAdmin() ? \Froxlor\FroxlorLogger::ADM_ACTION : \Froxlor\FroxlorLogger::USR_ACTION, LOG_INFO, "[API] edited domain '" . $idna_convert->decode($result['domain']) . "'");
 		}
@@ -1019,13 +1019,13 @@ class SubDomains extends \Froxlor\Api\ApiCommand implements \Froxlor\Api\Resourc
 			'domainid' => $id
 		), true, true);
 
-		\Froxlor\System\Cronjob::inserttask('1');
+		\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::REBUILD_VHOST);
 		// Using nameserver, insert a task which rebuilds the server config
-		\Froxlor\System\Cronjob::inserttask('4');
+		\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::REBUILD_DNS);
 		// remove domains DNS from powerDNS if used, #581
-		\Froxlor\System\Cronjob::inserttask('11', $result['domain']);
+		\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::DELETE_DOMAIN_PDNS, $result['domain']);
 		// remove domain from acme.sh / lets encrypt if used
-		\Froxlor\System\Cronjob::inserttask('12', $result['domain']);
+		\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::DELETE_DOMAIN_SSL, $result['domain']);
 
 		// reduce subdomain-usage-counter
 		Customers::decreaseUsage($customer['customerid'], 'subdomains_used');
diff --git a/lib/Froxlor/Cron/MasterCron.php b/lib/Froxlor/Cron/MasterCron.php
index 0c4c88e4..2f2b52a0 100644
--- a/lib/Froxlor/Cron/MasterCron.php
+++ b/lib/Froxlor/Cron/MasterCron.php
@@ -63,13 +63,13 @@ class MasterCron extends \Froxlor\Cron\FroxlorCron
 				if (strtolower($argv[$x]) == '--force') {
 					// really force re-generating of config-files by
 					// inserting task 1
-					\Froxlor\System\Cronjob::inserttask('1');
+					\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::REBUILD_VHOST);
 					// bind (if enabled, \Froxlor\System\Cronjob::inserttask() checks this)
-					\Froxlor\System\Cronjob::inserttask('4');
+					\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::REBUILD_DNS);
 					// set quotas (if enabled)
-					\Froxlor\System\Cronjob::inserttask('10');
+					\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::CREATE_QUOTA);
 					// also regenerate cron.d-file
-					\Froxlor\System\Cronjob::inserttask('99');
+					\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::REBUILD_CRON);
 					array_push($jobs_to_run, 'tasks');
 					define('CRON_IS_FORCED', 1);
 				} elseif (strtolower($argv[$x]) == '--debug') {
diff --git a/lib/Froxlor/Cron/System/TasksCron.php b/lib/Froxlor/Cron/System/TasksCron.php
index b78575f0..99c93944 100644
--- a/lib/Froxlor/Cron/System/TasksCron.php
+++ b/lib/Froxlor/Cron/System/TasksCron.php
@@ -4,6 +4,8 @@ namespace Froxlor\Cron\System;
 use Froxlor\Database\Database;
 use Froxlor\Settings;
 
+use Froxlor\Cron\TaskId;
+
 /**
  * This file is part of the Froxlor project.
  * Copyright (c) 2003-2009 the SysCP Team (see authors).
@@ -45,55 +47,55 @@ class TasksCron extends \Froxlor\Cron\FroxlorCron
 				$row['data'] = json_decode($row['data'], true);
 			}
 
-			if ($row['type'] == '1') {
+			if ($row['type'] == TaskId::REBUILD_VHOST) {
 				/**
 				 * TYPE=1 MEANS TO REBUILD APACHE VHOSTS.CONF
 				 */
 				self::rebuildWebserverConfigs();
-			} elseif ($row['type'] == '2') {
+			} elseif ($row['type'] == TaskId::CREATE_HOME) {
 				/**
 				 * TYPE=2 MEANS TO CREATE A NEW HOME AND CHOWN
 				 */
 				self::createNewHome($row);
-			} elseif ($row['type'] == '4' && (int) Settings::Get('system.bind_enable') != 0) {
+			} elseif ($row['type'] == TaskId::REBUILD_DNS && (int) Settings::Get('system.bind_enable') != 0) {
 				/**
 				 * TYPE=4 MEANS THAT SOMETHING IN THE BIND CONFIG HAS CHANGED.
 				 * REBUILD froxlor_bind.conf IF BIND IS ENABLED
 				 */
 				self::rebuildDnsConfigs();
-			} elseif ($row['type'] == '5') {
+			} elseif ($row['type'] == TaskId::CREATE_FTP) {
 				/**
 				 * TYPE=5 MEANS THAT A NEW FTP-ACCOUNT HAS BEEN CREATED, CREATE THE DIRECTORY
 				 */
 				self::createNewFtpHome($row);
-			} elseif ($row['type'] == '6') {
+			} elseif ($row['type'] == TaskId::DELETE_CUSTOMER_FILES) {
 				/**
 				 * TYPE=6 MEANS THAT A CUSTOMER HAS BEEN DELETED AND THAT WE HAVE TO REMOVE ITS FILES
 				 */
 				self::deleteCustomerData($row);
-			} elseif ($row['type'] == '7') {
+			} elseif ($row['type'] == TaskId::DELETE_EMAIL_DATA) {
 				/**
 				 * TYPE=7 Customer deleted an email account and wants the data to be deleted on the filesystem
 				 */
 				self::deleteEmailData($row);
-			} elseif ($row['type'] == '8') {
+			} elseif ($row['type'] == TaskId::DELETE_FTP_DATA) {
 				/**
 				 * TYPE=8 Customer deleted a ftp account and wants the homedir to be deleted on the filesystem
 				 * refs #293
 				 */
 				self::deleteFtpData($row);
-			} elseif ($row['type'] == '10' && (int) Settings::Get('system.diskquota_enabled') != 0) {
+			} elseif ($row['type'] == TaskId::CREATE_QUOTA && (int) Settings::Get('system.diskquota_enabled') != 0) {
 				/**
 				 * TYPE=10 Set the filesystem - quota
 				 */
 				self::setFilesystemQuota();
-			} elseif ($row['type'] == '11' && Settings::Get('system.dns_server') == 'PowerDNS') {
+			} elseif ($row['type'] == TaskId::DELETE_DOMAIN_PDNS && Settings::Get('system.dns_server') == 'PowerDNS') {
 				/**
 				 * TYPE=11 domain has been deleted, remove from pdns database if used
 				 */
 				\Froxlor\FroxlorLogger::getInstanceOf()->logAction(\Froxlor\FroxlorLogger::CRON_ACTION, LOG_NOTICE, "Removing PowerDNS entries for domain " . $row['data']['domain']);
 				\Froxlor\Dns\PowerDNS::cleanDomainZone($row['data']['domain']);
-			} elseif ($row['type'] == '12') {
+			} elseif ($row['type'] == TaskId::DELETE_DOMAIN_SSL) {
 				/**
 				 * TYPE=12 domain has been deleted, remove from acme.sh/let's encrypt directory if used
 				 */
diff --git a/lib/Froxlor/Cron/TaskId.php b/lib/Froxlor/Cron/TaskId.php
new file mode 100644
index 00000000..f862e2fe
--- /dev/null
+++ b/lib/Froxlor/Cron/TaskId.php
@@ -0,0 +1,105 @@
+<?php
+
+namespace Froxlor\Cron;
+
+
+class TaskId {
+	/**
+	 * TYPE=1 MEANS TO REBUILD APACHE VHOSTS.CONF
+	 */
+	const REBUILD_VHOST = 1;
+
+	/**
+	 * TYPE=2 MEANS TO CREATE A NEW HOME AND CHOWN
+	 */
+	const CREATE_HOME = 2;
+
+	/**
+	 * TYPE=4 MEANS THAT SOMETHING IN THE DNS CONFIG HAS CHANGED.
+	 * REBUILD froxlor_bind.conf IF BIND IS ENABLED, UPDATE DKIM KEYS
+	 */
+	const REBUILD_DNS = 4;
+
+	/**
+	 * TYPE=5 MEANS THAT A NEW FTP-ACCOUNT HAS BEEN CREATED, CREATE THE DIRECTORY
+	 */
+	const CREATE_FTP = 5;
+
+	/**
+	 * TYPE=6 MEANS THAT A CUSTOMER HAS BEEN DELETED AND THAT WE HAVE TO REMOVE ITS FILES
+	 */
+	const DELETE_CUSTOMER_FILES = 6;
+
+	/**
+	 * TYPE=7 Customer deleted an email account and wants the data to be deleted on the filesystem
+	 */
+	const DELETE_EMAIL_DATA = 7;
+
+	/**
+	 * TYPE=8 Customer deleted a ftp account and wants the homedir to be deleted on the filesystem
+	 * refs #293
+	 */
+	const DELETE_FTP_DATA = 8;
+
+	/**
+	 * TYPE=10 Set the filesystem - quota
+	 */
+	const CREATE_QUOTA = 10;
+
+	/**
+	 * TYPE=11 domain has been deleted, remove from pdns database if used
+	 */
+	const DELETE_DOMAIN_PDNS = 11;
+
+	/**
+	* TYPE=12 domain has been deleted, remove from acme.sh/let's encrypt directory if used
+	 */
+	const DELETE_DOMAIN_SSL = 12;
+
+	/**
+	* TYPE=20 COSTUMERBACKUP
+	 */
+	const CREATE_CUSTOMER_BACKUP = 20;
+
+	/**
+	* TYPE=99 REGENERATE CRON
+	 */
+	const REBUILD_CRON = 99;
+
+	/**
+	 * Return if a cron task id is valid
+	 * @param int|string $id cron task id (legacy string support)
+	 * @return boolean
+	 */
+	public static function isValid($id) {
+		static $reflContants;
+		if (!is_numeric($id)) {
+			return false;
+		}
+		$numericid = (int)$id;
+		if (!is_array($reflContants)) {
+			$reflClass = new \ReflectionClass(get_called_class());
+			$reflContants = $reflClass->getConstants();
+		}
+		return in_array($numericid, $reflContants, true);
+	}
+
+	/**
+	 * Get constant name by id
+	 * @param int|string $id cron task id (legacy string support)
+	 * @return string|false constant name or false if not found
+	 */
+	public static function convertToConstant($id) {
+		static $reflContants;
+		if (!is_numeric($id)) {
+			return false;
+		}
+		$numericid = (int)$id;
+		if (!is_array($reflContants)) {
+			$reflClass = new \ReflectionClass(get_called_class());
+			$reflContants = $reflClass->getConstants();
+		}
+		return array_search($numericid, $reflContants, true);
+	}
+}
+
diff --git a/lib/Froxlor/Settings/Store.php b/lib/Froxlor/Settings/Store.php
index 1f8a3a60..d282947c 100644
--- a/lib/Froxlor/Settings/Store.php
+++ b/lib/Froxlor/Settings/Store.php
@@ -174,7 +174,7 @@ class Store
 		$returnvalue = self::storeSettingField($fieldname, $fielddata, $newfieldvalue);
 
 		if ($returnvalue !== false) {
-			\Froxlor\System\Cronjob::inserttask('4');
+			\Froxlor\System\Cronjob::inserttask(\Froxlor\Cron\TaskId::REBUILD_DNS);
 		}
 		return $returnvalue;
 	}
diff --git a/lib/Froxlor/System/Cronjob.php b/lib/Froxlor/System/Cronjob.php
index a08dbaa0..030b555b 100644
--- a/lib/Froxlor/System/Cronjob.php
+++ b/lib/Froxlor/System/Cronjob.php
@@ -4,6 +4,8 @@ namespace Froxlor\System;
 use Froxlor\Settings;
 use Froxlor\Database\Database;
 
+use Froxlor\Cron\TaskId;
+
 class Cronjob
 {
 
@@ -109,13 +111,13 @@ class Cronjob
 			INSERT INTO `" . TABLE_PANEL_TASKS . "` SET `type` = :type, `data` = :data
 		");
 
-		if ($type == '1' || $type == '3' || $type == '4' || $type == '5' || $type == '10' || $type == '99') {
+		if ($type == TaskId::REBUILD_VHOST || $type == TaskId::REBUILD_DNS || $type == TaskId::CREATE_FTP || $type == TaskId::CREATE_QUOTA || $type == TaskId::REBUILD_CRON) {
 			// 4 = bind -> if bind disabled -> no task
-			if ($type == '4' && Settings::Get('system.bind_enable') == '0') {
+			if ($type == TaskId::REBUILD_DNS && Settings::Get('system.bind_enable') == '0') {
 				return;
 			}
 			// 10 = quota -> if quota disabled -> no task
-			if ($type == '10' && Settings::Get('system.diskquota_enabled') == '0') {
+			if ($type == TaskId::CREATE_QUOTA && Settings::Get('system.diskquota_enabled') == '0') {
 				return;
 			}
 
@@ -132,7 +134,7 @@ class Cronjob
 				'type' => $type,
 				'data' => ''
 			));
-		} elseif ($type == '2' && $param1 != '' && $param2 != '' && $param3 != '' && ($param4 == 0 || $param4 == 1)) {
+		} elseif ($type == TaskId::CREATE_HOME && $param1 != '' && $param2 != '' && $param3 != '' && ($param4 == 0 || $param4 == 1)) {
 			$data = array();
 			$data['loginname'] = $param1;
 			$data['uid'] = $param2;
@@ -140,56 +142,56 @@ class Cronjob
 			$data['store_defaultindex'] = $param4;
 			$data = json_encode($data);
 			Database::pexecute($ins_stmt, array(
-				'type' => '2',
+				'type' => TaskId::CREATE_HOME,
 				'data' => $data
 			));
-		} elseif ($type == '6' && $param1 != '') {
+		} elseif ($type == TaskId::DELETE_CUSTOMER_FILES && $param1 != '') {
 			$data = array();
 			$data['loginname'] = $param1;
 			$data = json_encode($data);
 			Database::pexecute($ins_stmt, array(
-				'type' => '6',
+				'type' => TaskId::DELETE_CUSTOMER_FILES,
 				'data' => $data
 			));
-		} elseif ($type == '7' && $param1 != '' && $param2 != '') {
+		} elseif ($type == TaskId::DELETE_EMAIL_DATA && $param1 != '' && $param2 != '') {
 			$data = array();
 			$data['loginname'] = $param1;
 			$data['email'] = $param2;
 			$data = json_encode($data);
 			Database::pexecute($ins_stmt, array(
-				'type' => '7',
+				'type' => TaskId::DELETE_EMAIL_DATA,
 				'data' => $data
 			));
-		} elseif ($type == '8' && $param1 != '' && $param2 != '') {
+		} elseif ($type == TaskId::DELETE_FTP_DATA && $param1 != '' && $param2 != '') {
 			$data = array();
 			$data['loginname'] = $param1;
 			$data['homedir'] = $param2;
 			$data = json_encode($data);
 			Database::pexecute($ins_stmt, array(
-				'type' => '8',
+				'type' => TaskId::DELETE_FTP_DATA,
 				'data' => $data
 			));
-		} elseif ($type == '11' && $param1 != '' && Settings::Get('system.bind_enable') == '1' && Settings::Get('system.dns_server') == 'PowerDNS') {
+		} elseif ($type == TaskId::DELETE_DOMAIN_PDNS && $param1 != '' && Settings::Get('system.bind_enable') == '1' && Settings::Get('system.dns_server') == 'PowerDNS') {
 			// -> if bind disabled or dns-server not PowerDNS -> no task
 			$data = array();
 			$data['domain'] = $param1;
 			$data = json_encode($data);
 			Database::pexecute($ins_stmt, array(
-				'type' => '11',
+				'type' => TaskId::DELETE_DOMAIN_PDNS,
 				'data' => $data
 			));
-		} elseif ($type == '12' && $param1 != '') {
+		} elseif ($type == TaskId::DELETE_DOMAIN_SSL && $param1 != '') {
 			$data = array();
 			$data['domain'] = $param1;
 			$data = json_encode($data);
 			Database::pexecute($ins_stmt, array(
-				'type' => '12',
+				'type' => TaskId::DELETE_DOMAIN_SSL,
 				'data' => $data
 			));
-		} elseif ($type == '20' && is_array($param1)) {
+		} elseif ($type == TaskId::CREATE_CUSTOMER_BACKUP && is_array($param1)) {
 			$data = json_encode($param1);
 			Database::pexecute($ins_stmt, array(
-				'type' => '20',
+				'type' => TaskId::CREATE_CUSTOMER_BACKUP,
 				'data' => $data
 			));
 		}
@@ -248,57 +250,23 @@ class Cronjob
 				$row['data'] = json_decode($row['data'], true);
 			}
 
-			// rebuilding webserver-configuration
-			if ($row['type'] == '1') {
-				$task_desc = $lng['tasks']['rebuild_webserverconfig'];
-			} elseif ($row['type'] == '2') {
-				// adding new user/
-				$loginname = '';
+			$task_id = $row['type'];
+			if (\Froxlor\Cron\TaskId::isValid($task_id)) {
+				$task_constname = \Froxlor\Cron\TaskId::convertToConstant($task_id);
+				$task_desc = isset($lng['tasks'][$task_constname]) ? $lng['tasks'][$task_constname] : $task_constname;
+				
 				if (is_array($row['data'])) {
-					$loginname = $row['data']['loginname'];
+					// task includes loginname
+					if (isset($row['data']['loginname'])) {
+						$loginname = $row['data']['loginname'];
+						$task_desc = str_replace('%loginname%', $loginname, $task_desc);
+					}
+					// task includes domain data
+					if (isset($row['data']['domain'])) {
+						$domain = $row['data']['domain'];
+						$task_desc = str_replace('%domain%', $domain, $task_desc);
+					}
 				}
-				$task_desc = $lng['tasks']['adding_customer'];
-				$task_desc = str_replace('%loginname%', $loginname, $task_desc);
-			} elseif ($row['type'] == '4') {
-				// rebuilding bind-configuration
-				$task_desc = $lng['tasks']['rebuild_bindconfig'];
-			} elseif ($row['type'] == '5') {
-				// creating ftp-user directory
-				$task_desc = $lng['tasks']['creating_ftpdir'];
-			} elseif ($row['type'] == '6') {
-				// deleting user-files
-				$loginname = '';
-				if (is_array($row['data'])) {
-					$loginname = $row['data']['loginname'];
-				}
-				$task_desc = $lng['tasks']['deleting_customerfiles'];
-				$task_desc = str_replace('%loginname%', $loginname, $task_desc);
-			} elseif ($row['type'] == '7') {
-				// deleting email-account
-				$task_desc = $lng['tasks']['remove_emailacc_files'];
-			} elseif ($row['type'] == '8') {
-				// deleting ftp-account
-				$task_desc = $lng['tasks']['remove_ftpacc_files'];
-			} elseif ($row['type'] == '10') {
-				// Set FS - quota
-				$task_desc = $lng['tasks']['diskspace_set_quota'];
-			} elseif ($row['type'] == '11') {
-				// remove domain from pdns database if used
-				$task_desc = sprintf($lng['tasks']['remove_pdns_domain'], $row['data']['domain']);
-			} elseif ($row['type'] == '12') {
-				// remove domains ssl files
-				$task_desc = sprintf($lng['tasks']['remove_ssl_domain'], $row['data']['domain']);
-			} elseif ($row['type'] == '20') {
-				// deleting user-files
-				$loginname = '';
-				if (is_array($row['data'])) {
-					$loginname = $row['data']['loginname'];
-				}
-				$task_desc = $lng['tasks']['backup_customerfiles'];
-				$task_desc = str_replace('%loginname%', $loginname, $task_desc);
-			} elseif ($row['type'] == '99') {
-				// re-generating of cron.d-file
-				$task_desc = $lng['tasks']['regenerating_crond'];
 			} else {
 				// unknown
 				$task_desc = "ERROR: Unknown task type '" . $row['type'] . "'";
diff --git a/lng/czech.lng.php b/lng/czech.lng.php
index 57340117..04c58dc6 100644
--- a/lng/czech.lng.php
+++ b/lng/czech.lng.php
@@ -954,11 +954,11 @@ $lng['update']['noupdatesavail'] = '<strong>You already have the latest Froxlor
 $lng['admin']['specialsettingsforsubdomains'] = 'Apply specialsettings to all subdomains (*.example.com)';
 $lng['serversettings']['specialsettingsforsubdomains']['description'] = 'If yes these custom vHost-settings will be added to all subdomains; if no subdomain-specialsettings are being removed.';
 $lng['tasks']['outstanding_tasks'] = 'Outstanding cron-tasks';
-$lng['tasks']['rebuild_webserverconfig'] = 'Rebuilding webserver-configuration';
-$lng['tasks']['adding_customer'] = 'Adding new customer %loginname%';
-$lng['tasks']['rebuild_bindconfig'] = 'Rebuilding bind-configuration';
-$lng['tasks']['creating_ftpdir'] = 'Creating directory for new ftp-user';
-$lng['tasks']['deleting_customerfiles'] = 'Deleting customer-files %loginname%';
+$lng['tasks']['REBUILD_VHOST'] = 'Rebuilding webserver-configuration';
+$lng['tasks']['CREATE_HOME'] = 'Adding new customer %loginname%';
+$lng['tasks']['REBUILD_DNS'] = 'Rebuilding bind-configuration';
+$lng['tasks']['CREATE_FTP'] = 'Creating directory for new ftp-user';
+$lng['tasks']['DELETE_CUSTOMER_FILES'] = 'Deleting customer-files %loginname%';
 $lng['tasks']['noneoutstanding'] = 'There are currently no outstanding tasks for Froxlor';
 
 // ADDED IN FROXLOR 0.9.1
@@ -1524,7 +1524,7 @@ $lng['serversettings']['diskquota_enabled'] = 'Kvóta aktivována?';
 $lng['serversettings']['diskquota_repquota_path']['description'] = 'Path to repquota';
 $lng['serversettings']['diskquota_quotatool_path']['description'] = 'Path to quotatool';
 $lng['serversettings']['diskquota_customer_partition']['description'] = 'Partition, on which the customer files are stored';
-$lng['tasks']['diskspace_set_quota'] = 'Set quota on filesystem';
+$lng['tasks']['CREATE_QUOTA'] = 'Set quota on filesystem';
 $lng['error']['session_timeout'] = 'Moc nízká hodnota';
 $lng['error']['session_timeout_desc'] = 'You should not set the session timeout lower than 1 minute.';
 
@@ -1554,7 +1554,7 @@ $lng['admin']['speciallogwarning'] = 'WARNING: By changing this setting you will
 // ADDED IN 0.9.28-svn2
 $lng['serversettings']['vmail_maildirname']['title'] = 'Maildir name';
 $lng['serversettings']['vmail_maildirname']['description'] = 'Maildir directory into user\'s account. Normally \'Maildir\', in some implementations \'.maildir\', and directly into user\'s directory if left blank.';
-$lng['tasks']['remove_emailacc_files'] = 'Delete customer e-mail data.';
+$lng['tasks']['DELETE_EMAIL_DATA'] = 'Delete customer e-mail data.';
 
 // ADDED IN 0.9.28-svn5
 $lng['error']['operationnotpermitted'] = 'Operace nepovolena!';
@@ -1683,8 +1683,8 @@ $lng['panel']['ftpdesc'] = 'FTP description';
 $lng['admin']['cronsettings'] = 'Cronjob settings';
 $lng['serversettings']['system_cronconfig']['title'] = 'Cron configuration file';
 $lng['serversettings']['system_cronconfig']['description'] = 'Path to the cron-service configuration-file. This file will be updated regularly and automatically by froxlor.<br />Note: Please <b>be sure</b> to use the same filename as for the main froxlor cronjob (default: /etc/cron.d/froxlor)!<br><br>If you are using <b>FreeBSD</b>, please specify <i>/etc/crontab</i> here!';
-$lng['tasks']['remove_ftpacc_files'] = 'Delete customer ftp-account data.';
-$lng['tasks']['regenerating_crond'] = 'Rebuilding the cron.d-file';
+$lng['tasks']['DELETE_FTP_DATA'] = 'Delete customer ftp-account data.';
+$lng['tasks']['REBUILD_CRON'] = 'Rebuilding the cron.d-file';
 $lng['serversettings']['system_crondreload']['title'] = 'Cron-daemon reload command';
 $lng['serversettings']['system_crondreload']['description'] = 'Specify the command to execute in order to reload your systems cron-daemon';
 $lng['admin']['integritycheck'] = 'Ověření databáze';
@@ -1889,7 +1889,7 @@ $lng['serversettings']['backupenabled']['title'] = "Povolit zálohy pro zákazn
 $lng['serversettings']['backupenabled']['description'] = "If activated, the customer will be able to schedule backup jobs (cron-backup) which generates an archive within his docroot (subdirectory chosable by customer)";
 $lng['extras']['path_protection_label'] = '<strong class="red">Important</strong>';
 $lng['extras']['path_protection_info'] = '<strong class="red">We strongly recommend protecting the given path, see "Extras" -> "Directory protection"</strong>';
-$lng['tasks']['backup_customerfiles'] = 'Backup job for customer %loginname%';
+$lng['tasks']['CREATE_CUSTOMER_BACKUP'] = 'Backup job for customer %loginname%';
 
 $lng['error']['dns_domain_nodns'] = 'DNS pro tuto doménu je vypnuto';
 $lng['error']['dns_content_empty'] = 'No content given';
@@ -2057,8 +2057,8 @@ $lng['panel']['ihave_configured'] = 'I have configured the services';
 $lng['panel']['system_is_configured'] = 'System is already set as configured';
 $lng['panel']['settings_before_configuration'] = 'Please be sure you adjusted the settings prior to configuring the services here';
 $lng['panel']['alternative_cmdline_config'] = 'Alternatively, just run the following command as root-user in your shell to configure the services automatically';
-$lng['tasks']['remove_pdns_domain'] = 'Delete domain %s from PowerDNS database';
-$lng['tasks']['remove_ssl_domain'] = 'Delete ssl files of domain %s';
+$lng['tasks']['DELETE_DOMAIN_PDNS'] = 'Delete domain %domain% from PowerDNS database';
+$lng['tasks']['DELETE_DOMAIN_SSL'] = 'Delete ssl files of domain %domain%';
 $lng['admin']['novhostcontainer'] = '<br><br><small class="red">None of the IPs and ports has the "' . $lng['admin']['ipsandports']['create_vhostcontainer'] . '" option enabled, many settings here will not be available</small>';
 $lng['serversettings']['errorlog_level']['title'] = 'Error log-level';
 $lng['serversettings']['errorlog_level']['description'] = 'Specify the error log level. Default is "warn" for apache-users and "error" for nginx-users.';
diff --git a/lng/dutch.lng.php b/lng/dutch.lng.php
index 6198b37a..e38c1202 100644
--- a/lng/dutch.lng.php
+++ b/lng/dutch.lng.php
@@ -862,11 +862,11 @@ $lng['update']['noupdatesavail'] = '<strong>U gebruikt reeds de meest recente ve
 $lng['admin']['specialsettingsforsubdomains'] = 'Speciale instellingen toepassen op alle subdomeinen (*.example.com)';
 $lng['serversettings']['specialsettingsforsubdomains']['description'] = 'Indien "Ja" zullen deze aangepaste VHost-instellingen worden toegepast op alle subdomeinen.';
 $lng['tasks']['outstanding_tasks'] = 'Uitstaande cron-taken';
-$lng['tasks']['rebuild_webserverconfig'] = 'Bezig met opnieuw opbouwen van de configuratie van de webserver';
-$lng['tasks']['adding_customer'] = 'Klant met naam %loginname% wordt toegevoegd';
-$lng['tasks']['rebuild_bindconfig'] = 'Opnieuw opbouwen bind-configuratie';
-$lng['tasks']['creating_ftpdir'] = 'Map aanmaken voor nieuwe FTP-gebruiker';
-$lng['tasks']['deleting_customerfiles'] = 'Verwijderen klantbestanden van %loginname%';
+$lng['tasks']['REBUILD_VHOST'] = 'Bezig met opnieuw opbouwen van de configuratie van de webserver';
+$lng['tasks']['CREATE_HOME'] = 'Klant met naam %loginname% wordt toegevoegd';
+$lng['tasks']['REBUILD_DNS'] = 'Opnieuw opbouwen bind-configuratie';
+$lng['tasks']['CREATE_FTP'] = 'Map aanmaken voor nieuwe FTP-gebruiker';
+$lng['tasks']['DELETE_CUSTOMER_FILES'] = 'Verwijderen klantbestanden van %loginname%';
 $lng['tasks']['noneoutstanding'] = 'Er zijn op dit moment geen uitstaande taken voor Froxlor';
 
 // ADDED IN FROXLOR 0.9.1
diff --git a/lng/english.lng.php b/lng/english.lng.php
index fdbcac52..0fe92d57 100644
--- a/lng/english.lng.php
+++ b/lng/english.lng.php
@@ -957,11 +957,11 @@ $lng['update']['noupdatesavail'] = '<strong>You already have the latest Froxlor
 $lng['admin']['specialsettingsforsubdomains'] = 'Apply specialsettings to all subdomains (*.example.com)';
 $lng['serversettings']['specialsettingsforsubdomains']['description'] = 'If yes these custom vHost-settings will be added to all subdomains; if no subdomain-specialsettings are being removed.';
 $lng['tasks']['outstanding_tasks'] = 'Outstanding cron-tasks';
-$lng['tasks']['rebuild_webserverconfig'] = 'Rebuilding webserver-configuration';
-$lng['tasks']['adding_customer'] = 'Adding new customer %loginname%';
-$lng['tasks']['rebuild_bindconfig'] = 'Rebuilding bind-configuration';
-$lng['tasks']['creating_ftpdir'] = 'Creating directory for new ftp-user';
-$lng['tasks']['deleting_customerfiles'] = 'Deleting customer-files %loginname%';
+$lng['tasks']['REBUILD_VHOST'] = 'Rebuilding webserver-configuration';
+$lng['tasks']['CREATE_HOME'] = 'Adding new customer %loginname%';
+$lng['tasks']['REBUILD_DNS'] = 'Rebuilding bind-configuration';
+$lng['tasks']['CREATE_FTP'] = 'Creating directory for new ftp-user';
+$lng['tasks']['DELETE_CUSTOMER_FILES'] = 'Deleting customer-files %loginname%';
 $lng['tasks']['noneoutstanding'] = 'There are currently no outstanding tasks for Froxlor';
 
 // ADDED IN FROXLOR 0.9.1
@@ -1527,7 +1527,7 @@ $lng['serversettings']['diskquota_enabled'] = 'Quota activated?';
 $lng['serversettings']['diskquota_repquota_path']['description'] = 'Path to repquota';
 $lng['serversettings']['diskquota_quotatool_path']['description'] = 'Path to quotatool';
 $lng['serversettings']['diskquota_customer_partition']['description'] = 'Partition, on which the customer files are stored';
-$lng['tasks']['diskspace_set_quota'] = 'Set quota on filesystem';
+$lng['tasks']['CREATE_QUOTA'] = 'Set quota on filesystem';
 $lng['error']['session_timeout'] = 'Value too low';
 $lng['error']['session_timeout_desc'] = 'You should not set the session timeout lower than 1 minute.';
 
@@ -1557,7 +1557,7 @@ $lng['admin']['speciallogwarning'] = 'WARNING: By changing this setting you will
 // ADDED IN 0.9.28-svn2
 $lng['serversettings']['vmail_maildirname']['title'] = 'Maildir name';
 $lng['serversettings']['vmail_maildirname']['description'] = 'Maildir directory into user\'s account. Normally \'Maildir\', in some implementations \'.maildir\', and directly into user\'s directory if left blank.';
-$lng['tasks']['remove_emailacc_files'] = 'Delete customer e-mail data.';
+$lng['tasks']['DELETE_EMAIL_DATA'] = 'Delete customer e-mail data.';
 
 // ADDED IN 0.9.28-svn5
 $lng['error']['operationnotpermitted'] = 'Operation not permitted!';
@@ -1688,8 +1688,8 @@ $lng['panel']['ftpdesc'] = 'FTP description';
 $lng['admin']['cronsettings'] = 'Cronjob settings';
 $lng['serversettings']['system_cronconfig']['title'] = 'Cron configuration file';
 $lng['serversettings']['system_cronconfig']['description'] = 'Path to the cron-service configuration-file. This file will be updated regularly and automatically by froxlor.<br />Note: Please <b>be sure</b> to use the same filename as for the main froxlor cronjob (default: /etc/cron.d/froxlor)!<br><br>If you are using <b>FreeBSD</b>, please specify <i>/etc/crontab</i> here!';
-$lng['tasks']['remove_ftpacc_files'] = 'Delete customer ftp-account data.';
-$lng['tasks']['regenerating_crond'] = 'Rebuilding the cron.d-file';
+$lng['tasks']['DELETE_FTP_DATA'] = 'Delete customer ftp-account data.';
+$lng['tasks']['REBUILD_CRON'] = 'Rebuilding the cron.d-file';
 $lng['serversettings']['system_crondreload']['title'] = 'Cron-daemon reload command';
 $lng['serversettings']['system_crondreload']['description'] = 'Specify the command to execute in order to reload your systems cron-daemon';
 $lng['admin']['integritycheck'] = 'Database validation';
@@ -1894,7 +1894,7 @@ $lng['serversettings']['backupenabled']['title'] = "Enable backup for customers"
 $lng['serversettings']['backupenabled']['description'] = "If activated, the customer will be able to schedule backup jobs (cron-backup) which generates an archive within his docroot (subdirectory chosable by customer)";
 $lng['extras']['path_protection_label'] = '<strong class="red">Important</strong>';
 $lng['extras']['path_protection_info'] = '<strong class="red">We strongly recommend protecting the given path, see "Extras" -> "Directory protection"</strong>';
-$lng['tasks']['backup_customerfiles'] = 'Backup job for customer %loginname%';
+$lng['tasks']['CREATE_CUSTOMER_BACKUP'] = 'Backup job for customer %loginname%';
 
 $lng['error']['dns_domain_nodns'] = 'DNS is not enabled for this domain';
 $lng['error']['dns_content_empty'] = 'No content given';
@@ -2063,8 +2063,8 @@ $lng['panel']['ihave_configured'] = 'I have configured the services';
 $lng['panel']['system_is_configured'] = 'System is already set as configured';
 $lng['panel']['settings_before_configuration'] = 'Please be sure you adjusted the settings prior to configuring the services here';
 $lng['panel']['alternative_cmdline_config'] = 'Alternatively, just run the following command as root-user in your shell to configure the services automatically';
-$lng['tasks']['remove_pdns_domain'] = 'Delete domain %s from PowerDNS database';
-$lng['tasks']['remove_ssl_domain'] = 'Delete ssl files of domain %s';
+$lng['tasks']['DELETE_DOMAIN_PDNS'] = 'Delete domain %domain% from PowerDNS database';
+$lng['tasks']['DELETE_DOMAIN_SSL'] = 'Delete ssl files of domain %domain%';
 $lng['admin']['novhostcontainer'] = '<br><br><small class="red">None of the IPs and ports has the "' . $lng['admin']['ipsandports']['create_vhostcontainer'] . '" option enabled, many settings here will not be available</small>';
 $lng['serversettings']['errorlog_level']['title'] = 'Error log-level';
 $lng['serversettings']['errorlog_level']['description'] = 'Specify the error log level. Default is "warn" for apache-users and "error" for nginx-users.';
diff --git a/lng/german.lng.php b/lng/german.lng.php
index a897f907..7be69d45 100644
--- a/lng/german.lng.php
+++ b/lng/german.lng.php
@@ -928,11 +928,11 @@ $lng['update']['noupdatesavail'] = '<strong>Ihre Froxlor-Version ist aktuell.</s
 $lng['admin']['specialsettingsforsubdomains'] = 'Übernehme Einstellungen für alle Subdomains (*.beispiel.de)';
 $lng['serversettings']['specialsettingsforsubdomains']['description'] = 'Wenn ja, werden die individuellen Einstellungen für alle Subdomains übernommen.<br />Wenn nein, werden Subdomain-Specialsettings entfernt.';
 $lng['tasks']['outstanding_tasks'] = 'Ausstehende Cron-Aufgaben';
-$lng['tasks']['rebuild_webserverconfig'] = 'Neuerstellung der Webserver-Konfiguration';
-$lng['tasks']['adding_customer'] = 'Erstelle neuen Kunden %loginname%';
-$lng['tasks']['rebuild_bindconfig'] = 'Neuerstellung der Bind-Konfiguration';
-$lng['tasks']['creating_ftpdir'] = 'Erstelle Verzeichnis für neuen FTP-Benutzer';
-$lng['tasks']['deleting_customerfiles'] = 'Löschen von Kunden-Dateien %loginname%';
+$lng['tasks']['REBUILD_VHOST'] = 'Neuerstellung der Webserver-Konfiguration';
+$lng['tasks']['CREATE_HOME'] = 'Erstelle neuen Kunden %loginname%';
+$lng['tasks']['REBUILD_DNS'] = 'Neuerstellung der Bind-Konfiguration';
+$lng['tasks']['CREATE_FTP'] = 'Erstelle Verzeichnis für neuen FTP-Benutzer';
+$lng['tasks']['DELETE_CUSTOMER_FILES'] = 'Löschen von Kunden-Dateien %loginname%';
 $lng['tasks']['noneoutstanding'] = 'Zur Zeit gibt es keine ausstehenden Aufgaben für Froxlor';
 
 // ADDED IN FROXLOR 0.9.1
@@ -1252,7 +1252,7 @@ $lng['serversettings']['diskquota_enabled'] = 'Quota aktiviert?';
 $lng['serversettings']['diskquota_repquota_path']['description'] = 'Pfad zu repquota';
 $lng['serversettings']['diskquota_quotatool_path']['description'] = 'Pfad zu quotatool';
 $lng['serversettings']['diskquota_customer_partition']['description'] = 'Partition, auf welcher die Kundendaten liegen';
-$lng['tasks']['diskspace_set_quota'] = 'Quota auf dem Dateisystem setzen';
+$lng['tasks']['CREATE_QUOTA'] = 'Quota auf dem Dateisystem setzen';
 $lng['error']['session_timeout'] = 'Wert zu niedrig';
 $lng['error']['session_timeout_desc'] = 'Der Wert der Session-Timeout sollte nicht unter einer Minute liegen.';
 
@@ -1281,7 +1281,7 @@ $lng['admin']['speciallogwarning'] = 'ACHTUNG: Durch diese Einstellungen werden
 // ADDED IN 0.9.28-svn2
 $lng['serversettings']['vmail_maildirname']['title'] = 'Maildir-(Unter-)Ordner';
 $lng['serversettings']['vmail_maildirname']['description'] = 'Der Maildir-Ordner innerhalb des Kontos des Benutzers (normalerweise \'Maildir\', in manchen Fällen auch \'.maildir\'). Sollen die E-Mails direkt in das Verzeichnis, diese Option leer lassen.';
-$lng['tasks']['remove_emailacc_files'] = 'E-Mail-Dateien des Kunden löschen';
+$lng['tasks']['DELETE_EMAIL_DATA'] = 'E-Mail-Dateien des Kunden löschen';
 
 // ADDED IN 0.9.28-svn5
 $lng['error']['operationnotpermitted'] = 'Diese Aktion ist nicht erlaubt!';
@@ -1411,8 +1411,8 @@ $lng['panel']['ftpdesc'] = 'FTP-Beschreibung';
 $lng['admin']['cronsettings'] = 'Cronjob-Einstellungen';
 $lng['serversettings']['system_cronconfig']['title'] = 'Cron-Konfigurationsdatei';
 $lng['serversettings']['system_cronconfig']['description'] = 'Pfad zur Konfigurationsdatei des Cron-Dienstes. Diese Datei wird von Froxlor automatisch aktualisiert.<br />Hinweis: Bitte verwenden Sie <strong>exakt</strong> die gleiche Datei wie für den Froxlor-Haupt-Cronjob (Standard: /etc/cron.d/froxlor)!<br><br>Wird <b>FreeBSD</b> verwendet, sollte hier <i>/etc/crontab</i> angegeben werden!';
-$lng['tasks']['remove_ftpacc_files'] = 'Kunden FTP-Konto Dateien löschen';
-$lng['tasks']['regenerating_crond'] = 'Neuerstellung der cron.d-Datei';
+$lng['tasks']['DELETE_FTP_DATA'] = 'Kunden FTP-Konto Dateien löschen';
+$lng['tasks']['REBUILD_CRON'] = 'Neuerstellung der cron.d-Datei';
 $lng['serversettings']['system_crondreload']['title'] = 'Cron-Daemon reload Befehl';
 $lng['serversettings']['system_crondreload']['description'] = 'Geben Sie hier den Befehl zum Neuladen des Cron-Daemons an';
 $lng['admin']['integritycheck'] = 'Datenbankpr&uuml;fung';
@@ -1544,7 +1544,7 @@ $lng['serversettings']['backupenabled']['title'] = "Backup für Kunden aktiviere
 $lng['serversettings']['backupenabled']['description'] = "Wenn dies aktiviert ist, kann der Kunde Sicherungen planen (cron-backup) welche ein Archiv in sein Heimatverzeichnis ablegt (Unterordner vom Kunden wählbar)";
 $lng['extras']['path_protection_label'] = '<strong class="red">Wichtig</strong>';
 $lng['extras']['path_protection_info'] = '<strong class="red">Wir raten dringend dazu den angegebenen Pfad zu schützen, siehe "Extras" -> "Verzeichnisschutz"</strong>';
-$lng['tasks']['backup_customerfiles'] = 'Datensicherung für Kunde %loginname%';
+$lng['tasks']['CREATE_CUSTOMER_BACKUP'] = 'Datensicherung für Kunde %loginname%';
 
 $lng['error']['dns_domain_nodns'] = 'DNS ist für diese Domain nicht aktiviert';
 $lng['error']['dns_content_empty'] = 'Keinen Inhalt angegeben';
@@ -1709,8 +1709,8 @@ $lng['panel']['ihave_configured'] = 'Ich habe die Dienste konfiguriert';
 $lng['panel']['system_is_configured'] = 'Das System ist bereits konfiguriert';
 $lng['panel']['settings_before_configuration'] = 'Stelle sicher, dass die Einstellungen angepasst wurden bevor die Dienste konfiguriert werden.';
 $lng['panel']['alternative_cmdline_config'] = 'Alternativ, führe den folgenden Befehl als root-Benutzer auf der Shell aus, um die Dienste automatisch zu konfigurieren.';
-$lng['tasks']['remove_pdns_domain'] = 'Lösche Domain %s von PowerDNS Datenbank';
-$lng['tasks']['remove_ssl_domain'] = 'Lösche SSL Dateien von Domain %s';
+$lng['tasks']['DELETE_DOMAIN_PDNS'] = 'Lösche Domain %domain% von PowerDNS Datenbank';
+$lng['tasks']['DELETE_DOMAIN_SSL'] = 'Lösche SSL Dateien von Domain %domain%';
 $lng['admin']['novhostcontainer'] = '<br><br><small class="red">Keine der IPs und Ports hat die Option "' . $lng['admin']['ipsandports']['create_vhostcontainer'] . '" aktiviert, einige Einstellungen sind daher nicht verfügbar.</small>';
 $lng['serversettings']['errorlog_level']['title'] = 'Ausführlichkeit des Fehlerprotokolls';
 $lng['serversettings']['errorlog_level']['description'] = 'Steuert die Ausführlichkeit des Fehlerprotokolls. Voreinstellung ist "warn" bei Apache und "error" bei Nginx.';
diff --git a/lng/italian.lng.php b/lng/italian.lng.php
index 0807cd92..24d937d3 100644
--- a/lng/italian.lng.php
+++ b/lng/italian.lng.php
@@ -884,11 +884,11 @@ $lng['update']['noupdatesavail'] = '<strong>È già presente l\'ultima versione
 $lng['admin']['specialsettingsforsubdomains'] = 'Applica le impostazioni speciali a tutti i sottodomini (*.esempio.com)';
 $lng['serversettings']['specialsettingsforsubdomains']['description'] = 'Se si queste impostazioni personalizzate dei vhost saranno aggiunte a tutti sottodomini; se no le impostazioni speciali dei sottodomini verranno rimosse.';
 $lng['tasks']['outstanding_tasks'] = 'Processi Cron in sospeso';
-$lng['tasks']['rebuild_webserverconfig'] = 'Ricostruzione della configurazione del webserver';
-$lng['tasks']['adding_customer'] = 'Aggiunto il nuovo cliente %loginname%';
-$lng['tasks']['rebuild_bindconfig'] = 'Ricostruzione della configurazione di bind';
-$lng['tasks']['creating_ftpdir'] = 'Creazione delle cartelle per i nuovi utenti ftp';
-$lng['tasks']['deleting_customerfiles'] = 'Eliminazione dei file del cliente %loginname%';
+$lng['tasks']['REBUILD_VHOST'] = 'Ricostruzione della configurazione del webserver';
+$lng['tasks']['CREATE_HOME'] = 'Aggiunto il nuovo cliente %loginname%';
+$lng['tasks']['REBUILD_DNS'] = 'Ricostruzione della configurazione di bind';
+$lng['tasks']['CREATE_FTP'] = 'Creazione delle cartelle per i nuovi utenti ftp';
+$lng['tasks']['DELETE_CUSTOMER_FILES'] = 'Eliminazione dei file del cliente %loginname%';
 $lng['tasks']['noneoutstanding'] = 'Attualmente non ci sono processi in sospeso per Froxlor';
 
 // ADDED IN FROXLOR 0.9.1
@@ -1486,7 +1486,7 @@ $lng['serversettings']['diskquota_enabled'] = 'Quota attivita?';
 $lng['serversettings']['diskquota_repquota_path']['description'] = 'Percorso a repquota';
 $lng['serversettings']['diskquota_quotatool_path']['description'] = 'Percorso al quotatool';
 $lng['serversettings']['diskquota_customer_partition']['description'] = 'Partizione, sulla quale sono salvati i dati dei clienti';
-$lng['tasks']['diskspace_set_quota'] = 'Setta quota al filesystem';
+$lng['tasks']['CREATE_QUOTA'] = 'Setta quota al filesystem';
 $lng['error']['session_timeout'] = 'Valore troppo basso';
 $lng['error']['session_timeout_desc'] = 'Non dovresti settare il timeout della sessione ad un valore minore di 1 minuto.';
 $lng['admin']['assignedmax'] = 'Assegnato / Max';
@@ -1506,7 +1506,7 @@ $lng['admin']['delete_statistics'] = 'Elimina Statistiche';
 $lng['admin']['speciallogwarning'] = 'AVVISO: Cambiando questa impostazione perderai tutte le vecchie statistiche per questo dominio. Se sei sicuro che vuoi cambiare questo digita "%s" nel campo sottostante e clicca il bottone "elimina".<br /><br />';
 $lng['serversettings']['vmail_maildirname']['title'] = 'nome Maildir';
 $lng['serversettings']['vmail_maildirname']['description'] = 'cartella Maildir nell account utente. Normalmente \'Maildir\', in alcune implementazioni \'.maildir\', e direttamente nella cartella utente se lasciato vuoto.';
-$lng['tasks']['remove_emailacc_files'] = 'Elimina i dati di posta elettronica del cliente.';
+$lng['tasks']['DELETE_EMAIL_DATA'] = 'Elimina i dati di posta elettronica del cliente.';
 $lng['error']['operationnotpermitted'] = 'Operazione non permessa!';
 $lng['error']['featureisdisabled'] = 'Funzionalità %s è disabilitata. Perfavore contatta il tuo fornitore di servizi.';
 $lng['serversettings']['catchall_enabled']['title'] = 'Usa Catchall';
@@ -1616,8 +1616,8 @@ $lng['admin']['cronsettings'] = 'Impostazioni Cronjob';
 $lng['serversettings']['system_cronconfig']['title'] = 'File di configurazione Cron';
 $lng['serversettings']['system_cronconfig']['description'] = 'Percorso al file di configurazione del servizio cron. Questo file verrà aggiornato regolarmente ed automaticamente da froxlor.<br />
 Nota: Perfavore <b>sii sicuro</b> di usare lo stesso nome di file come per il cronjob principale di froxlor (predefinito: /etc/cron.d/froxlor)!<br><br>Se usi <b>FreeBSD</b>, qui specifica: <i>/etc/crontab</i>!';
-$lng['tasks']['remove_ftpacc_files'] = 'Elimina i dati account-ftp del cliente.';
-$lng['tasks']['regenerating_crond'] = 'Ricostruisci il file cron.d';
+$lng['tasks']['DELETE_FTP_DATA'] = 'Elimina i dati account-ftp del cliente.';
+$lng['tasks']['REBUILD_CRON'] = 'Ricostruisci il file cron.d';
 $lng['serversettings']['system_crondreload']['title'] = 'Commando per riavviare il servizio Cron';
 $lng['serversettings']['system_crondreload']['description'] = 'Specifica il commando da eseguire per riavviare il servizio cron del tuo sistema';
 $lng['admin']['integritycheck'] = 'Validazione Database';
diff --git a/phpunit.xml b/phpunit.xml
index 94672a8c..aee8fd5b 100644
--- a/phpunit.xml
+++ b/phpunit.xml
@@ -30,6 +30,7 @@
       <directory>tests/PhpAndFpm</directory>
       <directory>tests/Traffic</directory>
       <directory>tests/Froxlor</directory>
+      <directory>tests/Cron</directory>
     </testsuite>
   </testsuites>
   <logging>
diff --git a/tests/Cron/TaskIdTest.php b/tests/Cron/TaskIdTest.php
new file mode 100644
index 00000000..397ffe87
--- /dev/null
+++ b/tests/Cron/TaskIdTest.php
@@ -0,0 +1,84 @@
+<?php
+use PHPUnit\Framework\TestCase;
+
+use Froxlor\Cron\TaskId;
+
+/**
+ *
+ * @covers \Froxlor\Cron\TaskId
+ */
+class TaskIDTest extends TestCase
+{
+	private $fixedids = array(
+		'REBUILD_VHOST' => 1,
+
+		'CREATE_HOME' => 2,
+
+		'REBUILD_DNS' => 4,
+
+		'CREATE_FTP' => 5,
+
+		'DELETE_CUSTOMER_FILES' => 6,
+
+		'DELETE_EMAIL_DATA' => 7,
+
+		'DELETE_FTP_DATA' => 8,
+
+		'CREATE_QUOTA' => 10,
+
+		'DELETE_DOMAIN_PDNS' => 11,
+
+		'DELETE_DOMAIN_SSL' => 12,
+
+		'CREATE_CUSTOMER_BACKUP' => 20,
+
+		'REBUILD_CRON' => 99,
+	);
+
+	public function testValidTaskId()
+	{
+
+		$isId99Valid = TaskId::isValid(99);
+		$this->assertTrue($isId99Valid, "Task id 99 must be valid");
+
+		$isIdStringValid = TaskId::isValid('99');
+		$this->assertTrue($isIdStringValid, "String task ids should be valid");
+
+		$isNegativeValid = TaskId::isValid(-1);
+		$this->assertFalse($isNegativeValid, "Negative task should be invalid");
+	}
+
+	public function testAcceptNewTaskId()
+	{
+		$isTESTTASKValid = TaskIdExtended::isValid(10101010);
+		$this->assertTrue($isTESTTASKValid);
+	}
+
+
+	public function testFixedTaskIdTable()
+	{
+		$isTESTTASKValid = TaskIdExtended::isValid(10101010);
+		$this->assertTrue($isTESTTASKValid);
+	}
+
+	public function testIdMappingCorrect() {
+		foreach($this->fixedids as $name => $expected) {
+			$result = constant("\Froxlor\Cron\TaskId::$name");
+			$this->assertEquals( $expected, $result, "Task $name has bad mapping");
+		}
+	}
+
+	public function testConvertToConstant() {
+		foreach($this->fixedids as $name => $taskid) {
+			$result = TaskId::convertToConstant($taskid);
+			$this->assertEquals( $name, $result, "Task $name has bad mapping from id to name");
+		}
+
+		$unknownIDResult = TaskId::isValid(10101010);
+		$this->assertFalse($unknownIDResult);
+	}
+}
+
+class TaskIdExtended extends TaskId {
+	const TESTTASK = 10101010;
+}