diff --git a/include/conversation.php b/include/conversation.php
index e276fef139..04f0adaef6 100644
--- a/include/conversation.php
+++ b/include/conversation.php
@@ -26,6 +26,7 @@ use Friendica\Object\Thread;
 use Friendica\Util\DateTimeFormat;
 use Friendica\Util\Proxy as ProxyUtils;
 use Friendica\Util\Temporal;
+use Friendica\Util\Strings;
 use Friendica\Util\XML;
 use Friendica\Util\Crypto;
 
@@ -482,7 +483,7 @@ function conversation(App $a, array $items, Pager $pager, $mode, $update, $previ
 		if (!$update) {
 			$tab = 'posts';
 			if (x($_GET, 'tab')) {
-				$tab = notags(trim($_GET['tab']));
+				$tab = Strings::removeTags(trim($_GET['tab']));
 			}
 			if ($tab === 'posts') {
 				/*
diff --git a/include/text.php b/include/text.php
index 08858fe0fc..b4e8dbf112 100644
--- a/include/text.php
+++ b/include/text.php
@@ -26,6 +26,7 @@ use Friendica\Util\Proxy as ProxyUtils;
 use Friendica\Core\Logger;
 use Friendica\Core\Renderer;
 use Friendica\Model\FileTag;
+use Friendica\Util\Strings;
 use Friendica\Util\XML;
 use Friendica\Content\Text\HTML;
 
@@ -61,7 +62,7 @@ function expand_acl($s) {
  */
 function sanitise_acl(&$item) {
 	if (intval($item)) {
-		$item = '<' . intval(notags(trim($item))) . '>';
+		$item = '<' . intval(Strings::removeTags(trim($item))) . '>';
 	} else {
 		unset($item);
 	}
diff --git a/mod/acl.php b/mod/acl.php
index a63cd83ae0..266c294178 100644
--- a/mod/acl.php
+++ b/mod/acl.php
@@ -12,6 +12,7 @@ use Friendica\Database\DBA;
 use Friendica\Model\Contact;
 use Friendica\Model\Item;
 use Friendica\Util\Proxy as ProxyUtils;
+use Friendica\Util\Strings;
 
 require_once 'include/dba.php';
 
@@ -188,7 +189,7 @@ function acl_content(App $a)
 		);
 	} elseif ($type == 'x') {
 		// autocomplete for global contact search (e.g. navbar search)
-		$search = notags(trim($_REQUEST['search']));
+		$search = Strings::removeTags(trim($_REQUEST['search']));
 		$mode = $_REQUEST['smode'];
 
 		$r = ACL::contactAutocomplete($search, $mode);
diff --git a/mod/admin.php b/mod/admin.php
index 272b97a887..0be43036be 100644
--- a/mod/admin.php
+++ b/mod/admin.php
@@ -30,6 +30,7 @@ use Friendica\Module\Tos;
 use Friendica\Util\Arrays;
 use Friendica\Util\DateTimeFormat;
 use Friendica\Util\Network;
+use Friendica\Util\Strings;
 use Friendica\Util\Temporal;
 
 require_once 'include/enotify.php';
@@ -416,8 +417,8 @@ function admin_page_blocklist_post(App $a)
 		//  Add new item to blocklist
 		$blocklist = Config::get('system', 'blocklist');
 		$blocklist[] = [
-			'domain' => notags(trim($_POST['newentry_domain'])),
-			'reason' => notags(trim($_POST['newentry_reason']))
+			'domain' => Strings::removeTags(trim($_POST['newentry_domain'])),
+			'reason' => Strings::removeTags(trim($_POST['newentry_reason']))
 		];
 		Config::set('system', 'blocklist', $blocklist);
 		info(L10n::t('Server added to blocklist.') . EOL);
@@ -426,8 +427,8 @@ function admin_page_blocklist_post(App $a)
 		$blocklist = [];
 		foreach ($_POST['domain'] as $id => $domain) {
 			// Trimming whitespaces as well as any lingering slashes
-			$domain = notags(trim($domain, "\x00..\x1F/"));
-			$reason = notags(trim($_POST['reason'][$id]));
+			$domain = Strings::removeTags(trim($domain, "\x00..\x1F/"));
+			$reason = Strings::removeTags(trim($_POST['reason'][$id]));
 			if (!x($_POST['delete'][$id])) {
 				$blocklist[] = [
 					'domain' => $domain,
@@ -565,7 +566,7 @@ function admin_page_deleteitem_post(App $a)
 	BaseModule::checkFormSecurityTokenRedirectOnError('/admin/deleteitem/', 'admin_deleteitem');
 
 	if (x($_POST['page_deleteitem_submit'])) {
-		$guid = trim(notags($_POST['deleteitemguid']));
+		$guid = trim(Strings::removeTags($_POST['deleteitemguid']));
 		// The GUID should not include a "/", so if there is one, we got an URL
 		// and the last part of it is most likely the GUID.
 		if (strpos($guid, '/')) {
@@ -1048,16 +1049,16 @@ function admin_page_site_post(App $a)
 	}
 	// end relocate
 
-	$sitename 		=	((x($_POST,'sitename'))			? notags(trim($_POST['sitename']))		: '');
-	$hostname 		=	((x($_POST,'hostname'))			? notags(trim($_POST['hostname']))		: '');
-	$sender_email		=	((x($_POST,'sender_email'))		? notags(trim($_POST['sender_email']))		: '');
+	$sitename 		=	((x($_POST,'sitename'))			? Strings::removeTags(trim($_POST['sitename']))		: '');
+	$hostname 		=	((x($_POST,'hostname'))			? Strings::removeTags(trim($_POST['hostname']))		: '');
+	$sender_email		=	((x($_POST,'sender_email'))		? Strings::removeTags(trim($_POST['sender_email']))		: '');
 	$banner			=	((x($_POST,'banner'))			? trim($_POST['banner'])			: false);
-	$shortcut_icon 		=	((x($_POST,'shortcut_icon'))		? notags(trim($_POST['shortcut_icon']))		: '');
-	$touch_icon 		=	((x($_POST,'touch_icon'))		? notags(trim($_POST['touch_icon']))		: '');
+	$shortcut_icon 		=	((x($_POST,'shortcut_icon'))		? Strings::removeTags(trim($_POST['shortcut_icon']))		: '');
+	$touch_icon 		=	((x($_POST,'touch_icon'))		? Strings::removeTags(trim($_POST['touch_icon']))		: '');
 	$info			=	((x($_POST,'info'))			? trim($_POST['info'])				: false);
-	$language		=	((x($_POST,'language'))			? notags(trim($_POST['language']))		: '');
-	$theme			=	((x($_POST,'theme'))			? notags(trim($_POST['theme']))			: '');
-	$theme_mobile		=	((x($_POST,'theme_mobile'))		? notags(trim($_POST['theme_mobile']))		: '');
+	$language		=	((x($_POST,'language'))			? Strings::removeTags(trim($_POST['language']))		: '');
+	$theme			=	((x($_POST,'theme'))			? Strings::removeTags(trim($_POST['theme']))			: '');
+	$theme_mobile		=	((x($_POST,'theme_mobile'))		? Strings::removeTags(trim($_POST['theme_mobile']))		: '');
 	$maximagesize		=	((x($_POST,'maximagesize'))		? intval(trim($_POST['maximagesize']))		:  0);
 	$maximagelength		=	((x($_POST,'maximagelength'))		? intval(trim($_POST['maximagelength']))	:  MAX_IMAGE_LENGTH);
 	$jpegimagequality	=	((x($_POST,'jpegimagequality'))		? intval(trim($_POST['jpegimagequality']))	:  JPEG_QUALITY);
@@ -1069,14 +1070,14 @@ function admin_page_site_post(App $a)
 
 	$register_text		=	((x($_POST,'register_text'))		? strip_tags(trim($_POST['register_text']))		: '');
 
-	$allowed_sites		=	((x($_POST,'allowed_sites'))		? notags(trim($_POST['allowed_sites']))		: '');
-	$allowed_email		=	((x($_POST,'allowed_email'))		? notags(trim($_POST['allowed_email']))		: '');
-	$forbidden_nicknames	=	((x($_POST,'forbidden_nicknames'))	? strtolower(notags(trim($_POST['forbidden_nicknames'])))		: '');
+	$allowed_sites		=	((x($_POST,'allowed_sites'))		? Strings::removeTags(trim($_POST['allowed_sites']))		: '');
+	$allowed_email		=	((x($_POST,'allowed_email'))		? Strings::removeTags(trim($_POST['allowed_email']))		: '');
+	$forbidden_nicknames	=	((x($_POST,'forbidden_nicknames'))	? strtolower(Strings::removeTags(trim($_POST['forbidden_nicknames'])))		: '');
 	$no_oembed_rich_content = x($_POST,'no_oembed_rich_content');
-	$allowed_oembed		=	((x($_POST,'allowed_oembed'))		? notags(trim($_POST['allowed_oembed']))		: '');
+	$allowed_oembed		=	((x($_POST,'allowed_oembed'))		? Strings::removeTags(trim($_POST['allowed_oembed']))		: '');
 	$block_public		=	((x($_POST,'block_public'))		? True						: False);
 	$force_publish		=	((x($_POST,'publish_all'))		? True						: False);
-	$global_directory	=	((x($_POST,'directory'))		? notags(trim($_POST['directory']))		: '');
+	$global_directory	=	((x($_POST,'directory'))		? Strings::removeTags(trim($_POST['directory']))		: '');
 	$newuser_private		=	((x($_POST,'newuser_private'))		? True					: False);
 	$enotify_no_content		=	((x($_POST,'enotify_no_content'))	? True					: False);
 	$private_addons			=	((x($_POST,'private_addons'))		? True					: False);
@@ -1091,8 +1092,8 @@ function admin_page_site_post(App $a)
 	$max_author_posts_community_page	=	((x($_POST,'max_author_posts_community_page'))	? intval(trim($_POST['max_author_posts_community_page']))	: 0);
 
 	$verifyssl		=	((x($_POST,'verifyssl'))		? True						: False);
-	$proxyuser		=	((x($_POST,'proxyuser'))		? notags(trim($_POST['proxyuser']))		: '');
-	$proxy			=	((x($_POST,'proxy'))			? notags(trim($_POST['proxy']))			: '');
+	$proxyuser		=	((x($_POST,'proxyuser'))		? Strings::removeTags(trim($_POST['proxyuser']))		: '');
+	$proxy			=	((x($_POST,'proxy'))			? Strings::removeTags(trim($_POST['proxy']))			: '');
 	$timeout		=	((x($_POST,'timeout'))			? intval(trim($_POST['timeout']))		: 60);
 	$maxloadavg		=	((x($_POST,'maxloadavg'))		? intval(trim($_POST['maxloadavg']))		: 50);
 	$maxloadavg_frontend	=	((x($_POST,'maxloadavg_frontend'))	? intval(trim($_POST['maxloadavg_frontend']))	: 50);
@@ -1116,16 +1117,16 @@ function admin_page_site_post(App $a)
 	$dbclean_expire_days	=	((x($_POST,'dbclean_expire_days'))	? intval($_POST['dbclean_expire_days'])		: 0);
 	$dbclean_unclaimed	=	((x($_POST,'dbclean_unclaimed'))	? intval($_POST['dbclean_unclaimed'])		: 0);
 	$suppress_tags		=	((x($_POST,'suppress_tags'))		? True   					: False);
-	$itemcache		=	((x($_POST,'itemcache'))		? notags(trim($_POST['itemcache']))		: '');
+	$itemcache		=	((x($_POST,'itemcache'))		? Strings::removeTags(trim($_POST['itemcache']))		: '');
 	$itemcache_duration	=	((x($_POST,'itemcache_duration'))	? intval($_POST['itemcache_duration'])		: 0);
 	$max_comments		=	((x($_POST,'max_comments'))		? intval($_POST['max_comments'])		: 0);
-	$temppath		=	((x($_POST,'temppath'))			? notags(trim($_POST['temppath']))		: '');
-	$basepath		=	((x($_POST,'basepath'))			? notags(trim($_POST['basepath']))		: '');
-	$singleuser		=	((x($_POST,'singleuser'))		? notags(trim($_POST['singleuser']))		: '');
+	$temppath		=	((x($_POST,'temppath'))			? Strings::removeTags(trim($_POST['temppath']))		: '');
+	$basepath		=	((x($_POST,'basepath'))			? Strings::removeTags(trim($_POST['basepath']))		: '');
+	$singleuser		=	((x($_POST,'singleuser'))		? Strings::removeTags(trim($_POST['singleuser']))		: '');
 	$proxy_disabled		=	((x($_POST,'proxy_disabled'))		? True						: False);
 	$only_tag_search	=	((x($_POST,'only_tag_search'))		? True						: False);
 	$rino			=	((x($_POST,'rino'))			? intval($_POST['rino'])			: 0);
-	$check_new_version_url	=	((x($_POST, 'check_new_version_url'))	?	notags(trim($_POST['check_new_version_url']))	: 'none');
+	$check_new_version_url	=	((x($_POST, 'check_new_version_url'))	?	Strings::removeTags(trim($_POST['check_new_version_url']))	: 'none');
 
 	$worker_queues		=	((x($_POST,'worker_queues'))		? intval($_POST['worker_queues'])		: 10);
 	$worker_dont_fork	=	((x($_POST,'worker_dont_fork'))		? True						: False);
@@ -1133,10 +1134,10 @@ function admin_page_site_post(App $a)
 	$worker_frontend	=	((x($_POST,'worker_frontend'))		? True						: False);
 
 	$relay_directly		=	((x($_POST,'relay_directly'))		? True						: False);
-	$relay_server		=	((x($_POST,'relay_server'))		? notags(trim($_POST['relay_server']))		: '');
+	$relay_server		=	((x($_POST,'relay_server'))		? Strings::removeTags(trim($_POST['relay_server']))		: '');
 	$relay_subscribe	=	((x($_POST,'relay_subscribe'))		? True						: False);
-	$relay_scope		=	((x($_POST,'relay_scope'))		? notags(trim($_POST['relay_scope']))		: '');
-	$relay_server_tags	=	((x($_POST,'relay_server_tags'))	? notags(trim($_POST['relay_server_tags']))	: '');
+	$relay_scope		=	((x($_POST,'relay_scope'))		? Strings::removeTags(trim($_POST['relay_scope']))		: '');
+	$relay_server_tags	=	((x($_POST,'relay_server_tags'))	? Strings::removeTags(trim($_POST['relay_server_tags']))	: '');
 	$relay_user_tags	=	((x($_POST,'relay_user_tags'))		? True						: False);
 
 	// Has the directory url changed? If yes, then resubmit the existing profiles there
@@ -2370,7 +2371,7 @@ function admin_page_logs_post(App $a)
 	if (x($_POST, "page_logs")) {
 		BaseModule::checkFormSecurityTokenRedirectOnError('/admin/logs', 'admin_logs');
 
-		$logfile   = ((x($_POST,'logfile'))   ? notags(trim($_POST['logfile']))  : '');
+		$logfile   = ((x($_POST,'logfile'))   ? Strings::removeTags(trim($_POST['logfile']))  : '');
 		$debugging = ((x($_POST,'debugging')) ? true                             : false);
 		$loglevel  = ((x($_POST,'loglevel'))  ? intval(trim($_POST['loglevel'])) : 0);
 
diff --git a/mod/dfrn_confirm.php b/mod/dfrn_confirm.php
index 8d4594c152..8871e3e8a0 100644
--- a/mod/dfrn_confirm.php
+++ b/mod/dfrn_confirm.php
@@ -85,7 +85,7 @@ function dfrn_confirm_post(App $a, $handsfree = null)
 			$cid      = 0;
 			$hidden   = intval(defaults($handsfree, 'hidden'  , 0));
 		} else {
-			$dfrn_id  = notags(trim(defaults($_POST, 'dfrn_id'   , '')));
+			$dfrn_id  = Strings::removeTags(trim(defaults($_POST, 'dfrn_id'   , '')));
 			$intro_id =      intval(defaults($_POST, 'intro_id'  , 0));
 			$duplex   =      intval(defaults($_POST, 'duplex'    , 0));
 			$cid      =      intval(defaults($_POST, 'contact_id', 0));
diff --git a/mod/dfrn_notify.php b/mod/dfrn_notify.php
index ba2332bcb1..90d3fb2b5d 100644
--- a/mod/dfrn_notify.php
+++ b/mod/dfrn_notify.php
@@ -39,15 +39,15 @@ function dfrn_notify_post(App $a) {
 		}
 	}
 
-	$dfrn_id      = ((x($_POST,'dfrn_id'))      ? notags(trim($_POST['dfrn_id']))   : '');
+	$dfrn_id      = ((x($_POST,'dfrn_id'))      ? Strings::removeTags(trim($_POST['dfrn_id']))   : '');
 	$dfrn_version = ((x($_POST,'dfrn_version')) ? (float) $_POST['dfrn_version']    : 2.0);
-	$challenge    = ((x($_POST,'challenge'))    ? notags(trim($_POST['challenge'])) : '');
+	$challenge    = ((x($_POST,'challenge'))    ? Strings::removeTags(trim($_POST['challenge'])) : '');
 	$data         = ((x($_POST,'data'))         ? $_POST['data']                    : '');
 	$key          = ((x($_POST,'key'))          ? $_POST['key']                     : '');
 	$rino_remote  = ((x($_POST,'rino'))         ? intval($_POST['rino'])            :  0);
 	$dissolve     = ((x($_POST,'dissolve'))     ? intval($_POST['dissolve'])        :  0);
-	$perm         = ((x($_POST,'perm'))         ? notags(trim($_POST['perm']))      : 'r');
-	$ssl_policy   = ((x($_POST,'ssl_policy'))   ? notags(trim($_POST['ssl_policy'])): 'none');
+	$perm         = ((x($_POST,'perm'))         ? Strings::removeTags(trim($_POST['perm']))      : 'r');
+	$ssl_policy   = ((x($_POST,'ssl_policy'))   ? Strings::removeTags(trim($_POST['ssl_policy'])): 'none');
 	$page         = ((x($_POST,'page'))         ? intval($_POST['page'])            :  0);
 
 	$forum = (($page == 1) ? 1 : 0);
@@ -254,7 +254,7 @@ function dfrn_notify_content(App $a) {
 		 * If this is a duplex communication, ours will be the opposite.
 		 */
 
-		$dfrn_id = notags(trim($_GET['dfrn_id']));
+		$dfrn_id = Strings::removeTags(trim($_GET['dfrn_id']));
 		$dfrn_version = (float) $_GET['dfrn_version'];
 		$rino_remote = ((x($_GET,'rino')) ? intval($_GET['rino']) : 0);
 		$type = "";
diff --git a/mod/dfrn_request.php b/mod/dfrn_request.php
index e5d5a3fe22..7b2b3fbf1c 100644
--- a/mod/dfrn_request.php
+++ b/mod/dfrn_request.php
@@ -76,7 +76,7 @@ function dfrn_request_post(App $a)
 	if ((x($_POST, 'localconfirm')) && ($_POST['localconfirm'] == 1)) {
 		// Ensure this is a valid request
 		if (local_user() && ($a->user['nickname'] == $a->argv[1]) && (x($_POST, 'dfrn_url'))) {
-			$dfrn_url = notags(trim($_POST['dfrn_url']));
+			$dfrn_url = Strings::removeTags(trim($_POST['dfrn_url']));
 			$aes_allow = (((x($_POST, 'aes_allow')) && ($_POST['aes_allow'] == 1)) ? 1 : 0);
 			$confirm_key = ((x($_POST, 'confirm_key')) ? $_POST['confirm_key'] : "");
 			$hidden = ((x($_POST, 'hidden-contact')) ? intval($_POST['hidden-contact']) : 0);
@@ -270,7 +270,7 @@ function dfrn_request_post(App $a)
 			}
 		}
 
-		$real_name = x($_POST, 'realname') ? notags(trim($_POST['realname'])) : '';
+		$real_name = x($_POST, 'realname') ? Strings::removeTags(trim($_POST['realname'])) : '';
 
 		$url = trim($_POST['dfrn_url']);
 		if (!strlen($url)) {
@@ -424,7 +424,7 @@ function dfrn_request_post(App $a)
 					intval($uid),
 					intval($contact_record['id']),
 					((x($_POST,'knowyou') && ($_POST['knowyou'] == 1)) ? 1 : 0),
-					DBA::escape(notags(trim(defaults($_POST, 'dfrn-request-message', '')))),
+					DBA::escape(Strings::removeTags(trim(defaults($_POST, 'dfrn-request-message', '')))),
 					DBA::escape($hash),
 					DBA::escape(DateTimeFormat::utcNow())
 				);
@@ -498,7 +498,7 @@ function dfrn_request_content(App $a)
 			return Login::form();
 		}
 
-		$dfrn_url = notags(trim(hex2bin($_GET['dfrn_url'])));
+		$dfrn_url = Strings::removeTags(trim(hex2bin($_GET['dfrn_url'])));
 		$aes_allow = x($_GET, 'aes_allow') && $_GET['aes_allow'] == 1 ? 1 : 0;
 		$confirm_key = x($_GET, 'confirm_key') ? $_GET['confirm_key'] : "";
 
diff --git a/mod/directory.php b/mod/directory.php
index 10eaa44922..122fd1aa55 100644
--- a/mod/directory.php
+++ b/mod/directory.php
@@ -15,6 +15,7 @@ use Friendica\Database\DBA;
 use Friendica\Model\Contact;
 use Friendica\Model\Profile;
 use Friendica\Util\Proxy as ProxyUtils;
+use Friendica\Util\Strings;
 
 function directory_init(App $a)
 {
@@ -47,9 +48,9 @@ function directory_content(App $a)
 	Nav::setSelected('directory');
 
 	if (x($a->data, 'search')) {
-		$search = notags(trim($a->data['search']));
+		$search = Strings::removeTags(trim($a->data['search']));
 	} else {
-		$search = ((x($_GET, 'search')) ? notags(trim(rawurldecode($_GET['search']))) : '');
+		$search = ((x($_GET, 'search')) ? Strings::removeTags(trim(rawurldecode($_GET['search']))) : '');
 	}
 
 	$gdirpath = '';
diff --git a/mod/dirfind.php b/mod/dirfind.php
index 2451beb18c..df4bda7227 100644
--- a/mod/dirfind.php
+++ b/mod/dirfind.php
@@ -20,6 +20,7 @@ use Friendica\Network\Probe;
 use Friendica\Protocol\PortableContact;
 use Friendica\Util\Network;
 use Friendica\Util\Proxy as ProxyUtils;
+use Friendica\Util\Strings;
 
 
 function dirfind_init(App $a) {
@@ -45,7 +46,7 @@ function dirfind_content(App $a, $prefix = "") {
 
 	$local = Config::get('system','poco_local_search');
 
-	$search = $prefix.notags(trim(defaults($_REQUEST, 'search', '')));
+	$search = $prefix.Strings::removeTags(trim(defaults($_REQUEST, 'search', '')));
 
 	$header = '';
 
diff --git a/mod/follow.php b/mod/follow.php
index 5c6c6d9d34..f69cb4abed 100644
--- a/mod/follow.php
+++ b/mod/follow.php
@@ -13,6 +13,7 @@ use Friendica\Model\Profile;
 use Friendica\Network\Probe;
 use Friendica\Database\DBA;
 use Friendica\Util\Proxy as ProxyUtils;
+use Friendica\Util\Strings;
 
 function follow_post(App $a)
 {
@@ -25,7 +26,7 @@ function follow_post(App $a)
 	}
 
 	$uid = local_user();
-	$url = notags(trim($_REQUEST['url']));
+	$url = Strings::removeTags(trim($_REQUEST['url']));
 	$return_path = 'contacts';
 
 	// Makes the connection request for friendica contacts easier
@@ -60,7 +61,7 @@ function follow_content(App $a)
 	}
 
 	$uid = local_user();
-	$url = notags(trim($_REQUEST['url']));
+	$url = Strings::removeTags(trim($_REQUEST['url']));
 
 	$submit = L10n::t('Submit Request');
 
diff --git a/mod/group.php b/mod/group.php
index 8b2ce9ca12..970fbba299 100644
--- a/mod/group.php
+++ b/mod/group.php
@@ -16,6 +16,7 @@ use Friendica\Database\DBA;
 use Friendica\Model;
 use Friendica\Module;
 use Friendica\Util\Security;
+use Friendica\Util\Strings;
 
 function group_init(App $a) {
 	if (local_user()) {
@@ -33,7 +34,7 @@ function group_post(App $a) {
 	if (($a->argc == 2) && ($a->argv[1] === 'new')) {
 		BaseModule::checkFormSecurityTokenRedirectOnError('/group/new', 'group_edit');
 
-		$name = notags(trim($_POST['groupname']));
+		$name = Strings::removeTags(trim($_POST['groupname']));
 		$r = Model\Group::create(local_user(), $name);
 		if ($r) {
 			info(L10n::t('Group created.') . EOL);
@@ -61,7 +62,7 @@ function group_post(App $a) {
 			return; // NOTREACHED
 		}
 		$group = $r[0];
-		$groupname = notags(trim($_POST['groupname']));
+		$groupname = Strings::removeTags(trim($_POST['groupname']));
 		if (strlen($groupname) && ($groupname != $group['name'])) {
 			$r = q("UPDATE `group` SET `name` = '%s' WHERE `uid` = %d AND `id` = %d",
 				DBA::escape($groupname),
diff --git a/mod/help.php b/mod/help.php
index 2c8f68ff35..83c2aa5ff3 100644
--- a/mod/help.php
+++ b/mod/help.php
@@ -10,6 +10,7 @@ use Friendica\Core\Config;
 use Friendica\Core\L10n;
 use Friendica\Core\Renderer;
 use Friendica\Core\System;
+use Friendica\Util\Strings;
 
 function load_doc_file($s)
 {
@@ -47,7 +48,7 @@ function help_content(App $a)
 		$title = basename($path);
 		$filename = $path;
 		$text = load_doc_file('doc/' . $path . '.md');
-		$a->page['title'] = L10n::t('Help:') . ' ' . str_replace('-', ' ', notags($title));
+		$a->page['title'] = L10n::t('Help:') . ' ' . str_replace('-', ' ', Strings::removeTags($title));
 	}
 
 	$home = load_doc_file('doc/Home.md');
diff --git a/mod/invite.php b/mod/invite.php
index 1e02ae9ca9..e63f81d4e8 100644
--- a/mod/invite.php
+++ b/mod/invite.php
@@ -17,6 +17,7 @@ use Friendica\Database\DBA;
 use Friendica\Protocol\Email;
 use Friendica\Util\DateTimeFormat;
 use Friendica\Util\Security;
+use Friendica\Util\Strings;
 
 function invite_post(App $a)
 {
@@ -40,7 +41,7 @@ function invite_post(App $a)
 
 
 	$recipients  = !empty($_POST['recipients']) ? explode("\n", $_POST['recipients']) : [];
-	$message     = !empty($_POST['message'])    ? notags(trim($_POST['message']))     : '';
+	$message     = !empty($_POST['message'])    ? Strings::removeTags(trim($_POST['message']))     : '';
 
 	$total = 0;
 
diff --git a/mod/item.php b/mod/item.php
index c86ed5e278..c2088c4542 100644
--- a/mod/item.php
+++ b/mod/item.php
@@ -36,6 +36,7 @@ use Friendica\Protocol\Email;
 use Friendica\Util\DateTimeFormat;
 use Friendica\Util\Emailer;
 use Friendica\Util\Security;
+use Friendica\Util\Strings;
 
 require_once 'include/enotify.php';
 require_once 'include/text.php';
@@ -203,7 +204,7 @@ function item_post(App $a) {
 		$objecttype        = $orig_post['object-type'];
 		$app               = $orig_post['app'];
 		$categories        = $orig_post['file'];
-		$title             = notags(trim($_REQUEST['title']));
+		$title             = Strings::removeTags(trim($_REQUEST['title']));
 		$body              = escape_tags(trim($_REQUEST['body']));
 		$private           = $orig_post['private'];
 		$pubmail_enabled   = $orig_post['pubmail'];
@@ -235,13 +236,13 @@ function item_post(App $a) {
 			$str_contact_deny  = perms2str(defaults($_REQUEST, 'contact_deny', ''));
 		}
 
-		$title             =      notags(trim(defaults($_REQUEST, 'title'   , '')));
-		$location          =      notags(trim(defaults($_REQUEST, 'location', '')));
-		$coord             =      notags(trim(defaults($_REQUEST, 'coord'   , '')));
-		$verb              =      notags(trim(defaults($_REQUEST, 'verb'    , '')));
-		$emailcc           =      notags(trim(defaults($_REQUEST, 'emailcc' , '')));
+		$title             =      Strings::removeTags(trim(defaults($_REQUEST, 'title'   , '')));
+		$location          =      Strings::removeTags(trim(defaults($_REQUEST, 'location', '')));
+		$coord             =      Strings::removeTags(trim(defaults($_REQUEST, 'coord'   , '')));
+		$verb              =      Strings::removeTags(trim(defaults($_REQUEST, 'verb'    , '')));
+		$emailcc           =      Strings::removeTags(trim(defaults($_REQUEST, 'emailcc' , '')));
 		$body              = escape_tags(trim(defaults($_REQUEST, 'body'    , '')));
-		$network           =      notags(trim(defaults($_REQUEST, 'network' , Protocol::DFRN)));
+		$network           =      Strings::removeTags(trim(defaults($_REQUEST, 'network' , Protocol::DFRN)));
 		$guid              =      System::createUUID();
 
 		$postopts = defaults($_REQUEST, 'postopts', '');
diff --git a/mod/like.php b/mod/like.php
index 296e563bf4..b8de3ff6a1 100644
--- a/mod/like.php
+++ b/mod/like.php
@@ -3,6 +3,7 @@
 use Friendica\App;
 use Friendica\Core\System;
 use Friendica\Model\Item;
+use Friendica\Util\Strings;
 
 require_once 'include/items.php';
 
@@ -12,13 +13,13 @@ function like_content(App $a) {
 	}
 
 
-	$verb = notags(trim($_GET['verb']));
+	$verb = Strings::removeTags(trim($_GET['verb']));
 
 	if (!$verb) {
 		$verb = 'like';
 	}
 
-	$item_id = (($a->argc > 1) ? notags(trim($a->argv[1])) : 0);
+	$item_id = (($a->argc > 1) ? Strings::removeTags(trim($a->argv[1])) : 0);
 
 	$r = Item::performLike($item_id, $verb);
 	if (!$r) {
diff --git a/mod/lostpass.php b/mod/lostpass.php
index ae94fbbbea..f4ee91efa1 100644
--- a/mod/lostpass.php
+++ b/mod/lostpass.php
@@ -11,6 +11,7 @@ use Friendica\Core\System;
 use Friendica\Database\DBA;
 use Friendica\Model\User;
 use Friendica\Util\DateTimeFormat;
+use Friendica\Util\Strings;
 
 require_once 'boot.php';
 require_once 'include/enotify.php';
@@ -18,7 +19,7 @@ require_once 'include/text.php';
 
 function lostpass_post(App $a)
 {
-	$loginame = notags(trim($_POST['login-name']));
+	$loginame = Strings::removeTags(trim($_POST['login-name']));
 	if (!$loginame) {
 		$a->internalRedirect();
 	}
diff --git a/mod/message.php b/mod/message.php
index 23c08f5a3c..959420bfe1 100644
--- a/mod/message.php
+++ b/mod/message.php
@@ -18,6 +18,7 @@ use Friendica\Model\Mail;
 use Friendica\Module\Login;
 use Friendica\Util\DateTimeFormat;
 use Friendica\Util\Proxy as ProxyUtils;
+use Friendica\Util\Strings;
 use Friendica\Util\Temporal;
 
 require_once 'include/conversation.php';
@@ -58,8 +59,8 @@ function message_post(App $a)
 		return;
 	}
 
-	$replyto   = x($_REQUEST, 'replyto')   ? notags(trim($_REQUEST['replyto']))   : '';
-	$subject   = x($_REQUEST, 'subject')   ? notags(trim($_REQUEST['subject']))   : '';
+	$replyto   = x($_REQUEST, 'replyto')   ? Strings::removeTags(trim($_REQUEST['replyto']))   : '';
+	$subject   = x($_REQUEST, 'subject')   ? Strings::removeTags(trim($_REQUEST['subject']))   : '';
 	$body      = x($_REQUEST, 'body')      ? escape_tags(trim($_REQUEST['body'])) : '';
 	$recipient = x($_REQUEST, 'messageto') ? intval($_REQUEST['messageto'])       : 0;
 
diff --git a/mod/network.php b/mod/network.php
index 26458a7a0e..5e5f095db1 100644
--- a/mod/network.php
+++ b/mod/network.php
@@ -28,6 +28,7 @@ use Friendica\Model\Profile;
 use Friendica\Module\Login;
 use Friendica\Util\DateTimeFormat;
 use Friendica\Util\Proxy as ProxyUtils;
+use Friendica\Util\Strings;
 
 require_once 'include/conversation.php';
 require_once 'include/items.php';
@@ -536,7 +537,7 @@ function networkThreadedView(App $a, $update, $parent)
 	$star  = intval(defaults($_GET, 'star' , 0));
 	$bmark = intval(defaults($_GET, 'bmark', 0));
 	$conv  = intval(defaults($_GET, 'conv' , 0));
-	$order = notags(defaults($_GET, 'order', 'comment'));
+	$order = Strings::removeTags(defaults($_GET, 'order', 'comment'));
 	$nets  =        defaults($_GET, 'nets' , '');
 
 	if ($cid) {
diff --git a/mod/oexchange.php b/mod/oexchange.php
index 296869aac9..f66dee8f00 100644
--- a/mod/oexchange.php
+++ b/mod/oexchange.php
@@ -8,6 +8,7 @@ use Friendica\Core\Renderer;
 use Friendica\Core\System;
 use Friendica\Module\Login;
 use Friendica\Util\Network;
+use Friendica\Util\Strings;
 
 function oexchange_init(App $a) {
 
@@ -33,13 +34,13 @@ function oexchange_content(App $a) {
 	}
 
 	$url = ((x($_REQUEST,'url') && strlen($_REQUEST['url']))
-		? urlencode(notags(trim($_REQUEST['url']))) : '');
+		? urlencode(Strings::removeTags(trim($_REQUEST['url']))) : '');
 	$title = ((x($_REQUEST,'title') && strlen($_REQUEST['title']))
-		? '&title=' . urlencode(notags(trim($_REQUEST['title']))) : '');
+		? '&title=' . urlencode(Strings::removeTags(trim($_REQUEST['title']))) : '');
 	$description = ((x($_REQUEST,'description') && strlen($_REQUEST['description']))
-		? '&description=' . urlencode(notags(trim($_REQUEST['description']))) : '');
+		? '&description=' . urlencode(Strings::removeTags(trim($_REQUEST['description']))) : '');
 	$tags = ((x($_REQUEST,'tags') && strlen($_REQUEST['tags']))
-		? '&tags=' . urlencode(notags(trim($_REQUEST['tags']))) : '');
+		? '&tags=' . urlencode(Strings::removeTags(trim($_REQUEST['tags']))) : '');
 
 	$s = Network::fetchUrl(System::baseUrl() . '/parse_url?f=&url=' . $url . $title . $description . $tags);
 
diff --git a/mod/openid.php b/mod/openid.php
index d1404ba804..663bc1cecb 100644
--- a/mod/openid.php
+++ b/mod/openid.php
@@ -10,6 +10,7 @@ use Friendica\Core\L10n;
 use Friendica\Core\Logger;
 use Friendica\Core\System;
 use Friendica\Database\DBA;
+use Friendica\Util\Strings;
 
 function openid_content(App $a) {
 
@@ -74,16 +75,16 @@ function openid_content(App $a) {
 			if (is_array($attr) && count($attr)) {
 				foreach ($attr as $k => $v) {
 					if ($k === 'namePerson/friendly') {
-						$nick = notags(trim($v));
+						$nick = Strings::removeTags(trim($v));
 					}
 					if($k === 'namePerson/first') {
-						$first = notags(trim($v));
+						$first = Strings::removeTags(trim($v));
 					}
 					if($k === 'namePerson') {
-						$args .= '&username=' . urlencode(notags(trim($v)));
+						$args .= '&username=' . urlencode(Strings::removeTags(trim($v)));
 					}
 					if ($k === 'contact/email') {
-						$args .= '&email=' . urlencode(notags(trim($v)));
+						$args .= '&email=' . urlencode(Strings::removeTags(trim($v)));
 					}
 					if ($k === 'media/image/aspect11') {
 						$photosq = bin2hex(trim($v));
@@ -107,7 +108,7 @@ function openid_content(App $a) {
 				$args .= '&photo=' . urlencode($photo);
 			}
 
-			$args .= '&openid_url=' . urlencode(notags(trim($authid)));
+			$args .= '&openid_url=' . urlencode(Strings::removeTags(trim($authid)));
 
 			$a->internalRedirect('register?' . $args);
 
diff --git a/mod/photos.php b/mod/photos.php
index 7a49f061a7..238c735858 100644
--- a/mod/photos.php
+++ b/mod/photos.php
@@ -31,6 +31,7 @@ use Friendica\Util\DateTimeFormat;
 use Friendica\Util\Map;
 use Friendica\Util\Security;
 use Friendica\Util\Temporal;
+use Friendica\Util\Strings;
 use Friendica\Util\XML;
 
 require_once 'include/items.php';
@@ -222,7 +223,7 @@ function photos_post(App $a)
 		}
 
 		// RENAME photo album
-		$newalbum = notags(trim($_POST['albumname']));
+		$newalbum = Strings::removeTags(trim($_POST['albumname']));
 		if ($newalbum != $album) {
 			q("UPDATE `photo` SET `album` = '%s' WHERE `album` = '%s' AND `uid` = %d",
 				DBA::escape($newalbum),
@@ -365,11 +366,11 @@ function photos_post(App $a)
 	}
 
 	if ($a->argc > 2 && (!empty($_POST['desc']) || !empty($_POST['newtag']) || !empty($_POST['albname']) !== false)) {
-		$desc        = !empty($_POST['desc'])      ? notags(trim($_POST['desc']))      : '';
-		$rawtags     = !empty($_POST['newtag'])    ? notags(trim($_POST['newtag']))    : '';
+		$desc        = !empty($_POST['desc'])      ? Strings::removeTags(trim($_POST['desc']))      : '';
+		$rawtags     = !empty($_POST['newtag'])    ? Strings::removeTags(trim($_POST['newtag']))    : '';
 		$item_id     = !empty($_POST['item_id'])   ? intval($_POST['item_id'])         : 0;
-		$albname     = !empty($_POST['albname'])   ? notags(trim($_POST['albname']))   : '';
-		$origaname   = !empty($_POST['origaname']) ? notags(trim($_POST['origaname'])) : '';
+		$albname     = !empty($_POST['albname'])   ? Strings::removeTags(trim($_POST['albname']))   : '';
+		$origaname   = !empty($_POST['origaname']) ? Strings::removeTags(trim($_POST['origaname'])) : '';
 
 		$str_group_allow   = !empty($_POST['group_allow'])   ? perms2str($_POST['group_allow'])   : '';
 		$str_contact_allow = !empty($_POST['contact_allow']) ? perms2str($_POST['contact_allow']) : '';
@@ -707,8 +708,8 @@ function photos_post(App $a)
 	Addon::callHooks('photo_post_init', $_POST);
 
 	// Determine the album to use
-	$album    = !empty($_REQUEST['album'])    ? notags(trim($_REQUEST['album']))    : '';
-	$newalbum = !empty($_REQUEST['newalbum']) ? notags(trim($_REQUEST['newalbum'])) : '';
+	$album    = !empty($_REQUEST['album'])    ? Strings::removeTags(trim($_REQUEST['album']))    : '';
+	$newalbum = !empty($_REQUEST['newalbum']) ? Strings::removeTags(trim($_REQUEST['newalbum'])) : '';
 
 	Logger::log('mod/photos.php: photos_post(): album= ' . $album . ' newalbum= ' . $newalbum , Logger::DEBUG);
 
diff --git a/mod/poco.php b/mod/poco.php
index 08677ef8d4..0a369502d3 100644
--- a/mod/poco.php
+++ b/mod/poco.php
@@ -15,6 +15,7 @@ use Friendica\Core\System;
 use Friendica\Database\DBA;
 use Friendica\Protocol\PortableContact;
 use Friendica\Util\DateTimeFormat;
+use Friendica\Util\Strings;
 use Friendica\Util\XML;
 
 function poco_init(App $a) {
@@ -25,7 +26,7 @@ function poco_init(App $a) {
 	}
 
 	if ($a->argc > 1) {
-		$user = notags(trim($a->argv[1]));
+		$user = Strings::removeTags(trim($a->argv[1]));
 	}
 	if (empty($user)) {
 		$c = q("SELECT * FROM `pconfig` WHERE `cat` = 'system' AND `k` = 'suggestme' AND `v` = 1");
diff --git a/mod/poke.php b/mod/poke.php
index e8c43213a7..615e244e54 100644
--- a/mod/poke.php
+++ b/mod/poke.php
@@ -22,6 +22,7 @@ use Friendica\Core\System;
 use Friendica\Core\Worker;
 use Friendica\Database\DBA;
 use Friendica\Model\Item;
+use Friendica\Util\Strings;
 use Friendica\Util\XML;
 
 require_once 'include/items.php';
@@ -38,7 +39,7 @@ function poke_init(App $a)
 		return;
 	}
 
-	$verb = notags(trim($_GET['verb']));
+	$verb = Strings::removeTags(trim($_GET['verb']));
 
 	$verbs = L10n::getPokeVerbs();
 
diff --git a/mod/profile.php b/mod/profile.php
index cfbe07dadb..a006c88682 100644
--- a/mod/profile.php
+++ b/mod/profile.php
@@ -24,6 +24,7 @@ use Friendica\Protocol\ActivityPub;
 use Friendica\Protocol\DFRN;
 use Friendica\Util\DateTimeFormat;
 use Friendica\Util\Security;
+use Friendica\Util\Strings;
 use Friendica\Util\XML;
 
 function profile_init(App $a)
@@ -193,7 +194,7 @@ function profile_content(App $a, $update = 0)
 	if (!$update) {
 		$tab = false;
 		if (!empty($_GET['tab'])) {
-			$tab = notags(trim($_GET['tab']));
+			$tab = Strings::removeTags(trim($_GET['tab']));
 		}
 
 		$o .= Profile::getTabs($a, $is_owner, $a->profile['nickname']);
diff --git a/mod/profiles.php b/mod/profiles.php
index a535f2fc20..d6faadd44a 100644
--- a/mod/profiles.php
+++ b/mod/profiles.php
@@ -22,6 +22,7 @@ use Friendica\Model\Profile;
 use Friendica\Module\Login;
 use Friendica\Network\Probe;
 use Friendica\Util\DateTimeFormat;
+use Friendica\Util\Strings;
 use Friendica\Util\Temporal;
 
 function profiles_init(App $a) {
@@ -201,7 +202,7 @@ function profiles_post(App $a) {
 
 		$is_default = (($orig[0]['is-default']) ? 1 : 0);
 
-		$profile_name = notags(trim($_POST['profile_name']));
+		$profile_name = Strings::removeTags(trim($_POST['profile_name']));
 		if (! strlen($profile_name)) {
 			notice(L10n::t('Profile Name is required.') . EOL);
 			return;
@@ -228,7 +229,7 @@ function profiles_post(App $a) {
 			}
 		}
 
-		$name = notags(trim($_POST['name']));
+		$name = Strings::removeTags(trim($_POST['name']));
 
 		if (! strlen($name)) {
 			$name = '[No Name]';
@@ -238,19 +239,19 @@ function profiles_post(App $a) {
 			$namechanged = true;
 		}
 
-		$pdesc = notags(trim($_POST['pdesc']));
-		$gender = notags(trim($_POST['gender']));
-		$address = notags(trim($_POST['address']));
-		$locality = notags(trim($_POST['locality']));
-		$region = notags(trim($_POST['region']));
-		$postal_code = notags(trim($_POST['postal_code']));
-		$country_name = notags(trim($_POST['country_name']));
-		$pub_keywords = profile_clean_keywords(notags(trim($_POST['pub_keywords'])));
-		$prv_keywords = profile_clean_keywords(notags(trim($_POST['prv_keywords'])));
-		$marital = notags(trim($_POST['marital']));
-		$howlong = notags(trim($_POST['howlong']));
+		$pdesc = Strings::removeTags(trim($_POST['pdesc']));
+		$gender = Strings::removeTags(trim($_POST['gender']));
+		$address = Strings::removeTags(trim($_POST['address']));
+		$locality = Strings::removeTags(trim($_POST['locality']));
+		$region = Strings::removeTags(trim($_POST['region']));
+		$postal_code = Strings::removeTags(trim($_POST['postal_code']));
+		$country_name = Strings::removeTags(trim($_POST['country_name']));
+		$pub_keywords = profile_clean_keywords(Strings::removeTags(trim($_POST['pub_keywords'])));
+		$prv_keywords = profile_clean_keywords(Strings::removeTags(trim($_POST['prv_keywords'])));
+		$marital = Strings::removeTags(trim($_POST['marital']));
+		$howlong = Strings::removeTags(trim($_POST['howlong']));
 
-		$with = ((x($_POST,'with')) ? notags(trim($_POST['with'])) : '');
+		$with = ((x($_POST,'with')) ? Strings::removeTags(trim($_POST['with'])) : '');
 
 		if (! strlen($howlong)) {
 			$howlong = DBA::NULL_DATETIME;
@@ -311,16 +312,16 @@ function profiles_post(App $a) {
 		}
 
 		/// @TODO Not flexible enough for later expansion, let's have more OOP here
-		$sexual = notags(trim($_POST['sexual']));
-		$xmpp = notags(trim($_POST['xmpp']));
-		$homepage = notags(trim($_POST['homepage']));
+		$sexual = Strings::removeTags(trim($_POST['sexual']));
+		$xmpp = Strings::removeTags(trim($_POST['xmpp']));
+		$homepage = Strings::removeTags(trim($_POST['homepage']));
 		if ((strpos($homepage, 'http') !== 0) && (strlen($homepage))) {
 			// neither http nor https in URL, add them
 			$homepage = 'http://'.$homepage;
 		}
-		$hometown = notags(trim($_POST['hometown']));
-		$politic = notags(trim($_POST['politic']));
-		$religion = notags(trim($_POST['religion']));
+		$hometown = Strings::removeTags(trim($_POST['hometown']));
+		$politic = Strings::removeTags(trim($_POST['politic']));
+		$religion = Strings::removeTags(trim($_POST['religion']));
 
 		$likes = escape_tags(trim($_POST['likes']));
 		$dislikes = escape_tags(trim($_POST['dislikes']));
diff --git a/mod/pubsub.php b/mod/pubsub.php
index e14d500865..edab03e3f4 100644
--- a/mod/pubsub.php
+++ b/mod/pubsub.php
@@ -6,6 +6,7 @@ use Friendica\Core\Protocol;
 use Friendica\Database\DBA;
 use Friendica\Model\Contact;
 use Friendica\Protocol\OStatus;
+use Friendica\Util\Strings;
 
 require_once 'include/items.php';
 
@@ -30,15 +31,15 @@ function hub_post_return()
 
 function pubsub_init(App $a)
 {
-	$nick       = (($a->argc > 1) ? notags(trim($a->argv[1])) : '');
+	$nick       = (($a->argc > 1) ? Strings::removeTags(trim($a->argv[1])) : '');
 	$contact_id = (($a->argc > 2) ? intval($a->argv[2])       : 0 );
 
 	if ($_SERVER['REQUEST_METHOD'] === 'GET') {
-		$hub_mode      = notags(trim(defaults($_GET, 'hub_mode', '')));
-		$hub_topic     = notags(trim(defaults($_GET, 'hub_topic', '')));
-		$hub_challenge = notags(trim(defaults($_GET, 'hub_challenge', '')));
-		$hub_lease     = notags(trim(defaults($_GET, 'hub_lease_seconds', '')));
-		$hub_verify    = notags(trim(defaults($_GET, 'hub_verify_token', '')));
+		$hub_mode      = Strings::removeTags(trim(defaults($_GET, 'hub_mode', '')));
+		$hub_topic     = Strings::removeTags(trim(defaults($_GET, 'hub_topic', '')));
+		$hub_challenge = Strings::removeTags(trim(defaults($_GET, 'hub_challenge', '')));
+		$hub_lease     = Strings::removeTags(trim(defaults($_GET, 'hub_lease_seconds', '')));
+		$hub_verify    = Strings::removeTags(trim(defaults($_GET, 'hub_verify_token', '')));
 
 		Logger::log('Subscription from ' . $_SERVER['REMOTE_ADDR'] . ' Mode: ' . $hub_mode . ' Nick: ' . $nick);
 		Logger::log('Data: ' . print_r($_GET,true), Logger::DATA);
@@ -91,7 +92,7 @@ function pubsub_post(App $a)
 	Logger::log('Feed arrived from ' . $_SERVER['REMOTE_ADDR'] . ' for ' .  $a->cmd . ' with user-agent: ' . $_SERVER['HTTP_USER_AGENT']);
 	Logger::log('Data: ' . $xml, Logger::DATA);
 
-	$nick       = (($a->argc > 1) ? notags(trim($a->argv[1])) : '');
+	$nick       = (($a->argc > 1) ? Strings::removeTags(trim($a->argv[1])) : '');
 	$contact_id = (($a->argc > 2) ? intval($a->argv[2])       : 0 );
 
 	$importer = DBA::selectFirst('user', [], ['nickname' => $nick, 'account_expired' => false, 'account_removed' => false]);
diff --git a/mod/pubsubhubbub.php b/mod/pubsubhubbub.php
index 26a157e2fd..d23f1fe47d 100644
--- a/mod/pubsubhubbub.php
+++ b/mod/pubsubhubbub.php
@@ -7,9 +7,10 @@ use Friendica\Core\System;
 use Friendica\Database\DBA;
 use Friendica\Model\PushSubscriber;
 use Friendica\Util\Network;
+use Friendica\Util\Strings;
 
 function post_var($name) {
-	return (x($_POST, $name)) ? notags(trim($_POST[$name])) : '';
+	return (x($_POST, $name)) ? Strings::removeTags(trim($_POST[$name])) : '';
 }
 
 function pubsubhubbub_init(App $a) {
diff --git a/mod/register.php b/mod/register.php
index d8231bd21e..74e6bcf699 100644
--- a/mod/register.php
+++ b/mod/register.php
@@ -16,6 +16,7 @@ use Friendica\Core\System;
 use Friendica\Core\Worker;
 use Friendica\Model;
 use Friendica\Module\Tos;
+use Friendica\Util\Strings;
 
 require_once 'include/enotify.php';
 
@@ -83,7 +84,7 @@ function register_post(App $a)
 
 	$using_invites = Config::get('system', 'invitation_only');
 	$num_invites   = Config::get('system', 'number_invites');
-	$invite_id = ((x($_POST, 'invite_id')) ? notags(trim($_POST['invite_id'])) : '');
+	$invite_id = ((x($_POST, 'invite_id')) ? Strings::removeTags(trim($_POST['invite_id'])) : '');
 
 	if (intval(Config::get('config', 'register_policy')) === REGISTER_OPEN) {
 		if ($using_invites && $invite_id) {
diff --git a/mod/salmon.php b/mod/salmon.php
index 23e4e88846..e549b3d0f8 100644
--- a/mod/salmon.php
+++ b/mod/salmon.php
@@ -12,6 +12,7 @@ use Friendica\Model\Contact;
 use Friendica\Protocol\OStatus;
 use Friendica\Protocol\Salmon;
 use Friendica\Util\Crypto;
+use Friendica\Util\Strings;
 
 require_once 'include/items.php';
 
@@ -23,7 +24,7 @@ function salmon_post(App $a, $xml = '') {
 
 	Logger::log('new salmon ' . $xml, Logger::DATA);
 
-	$nick       = (($a->argc > 1) ? notags(trim($a->argv[1])) : '');
+	$nick       = (($a->argc > 1) ? Strings::removeTags(trim($a->argv[1])) : '');
 	$mentions   = (($a->argc > 2 && $a->argv[2] === 'mention') ? true : false);
 
 	$r = q("SELECT * FROM `user` WHERE `nickname` = '%s' AND `account_expired` = 0 AND `account_removed` = 0 LIMIT 1",
diff --git a/mod/search.php b/mod/search.php
index 809a6f7e86..9824c489a6 100644
--- a/mod/search.php
+++ b/mod/search.php
@@ -16,6 +16,7 @@ use Friendica\Core\Renderer;
 use Friendica\Core\System;
 use Friendica\Database\DBA;
 use Friendica\Model\Item;
+use Friendica\Util\Strings;
 
 require_once 'include/conversation.php';
 require_once 'mod/dirfind.php';
@@ -23,7 +24,7 @@ require_once 'mod/dirfind.php';
 function search_saved_searches() {
 
 	$o = '';
-	$search = ((x($_GET,'search')) ? notags(trim(rawurldecode($_GET['search']))) : '');
+	$search = ((x($_GET,'search')) ? Strings::removeTags(trim(rawurldecode($_GET['search']))) : '');
 
 	if (!Feature::isEnabled(local_user(),'savedsearch'))
 		return $o;
@@ -62,7 +63,7 @@ function search_saved_searches() {
 
 function search_init(App $a) {
 
-	$search = ((x($_GET,'search')) ? notags(trim(rawurldecode($_GET['search']))) : '');
+	$search = ((x($_GET,'search')) ? Strings::removeTags(trim(rawurldecode($_GET['search']))) : '');
 
 	if (local_user()) {
 		if (x($_GET,'save') && $search) {
@@ -149,14 +150,14 @@ function search_content(App $a) {
 
 	$search = '';
 	if (x($a->data,'search'))
-		$search = notags(trim($a->data['search']));
+		$search = Strings::removeTags(trim($a->data['search']));
 	else
-		$search = ((x($_GET,'search')) ? notags(trim(rawurldecode($_GET['search']))) : '');
+		$search = ((x($_GET,'search')) ? Strings::removeTags(trim(rawurldecode($_GET['search']))) : '');
 
 	$tag = false;
 	if (x($_GET,'tag')) {
 		$tag = true;
-		$search = (x($_GET,'tag') ? '#' . notags(trim(rawurldecode($_GET['tag']))) : '');
+		$search = (x($_GET,'tag') ? '#' . Strings::removeTags(trim(rawurldecode($_GET['tag']))) : '');
 	}
 
 	// contruct a wrapper for the search header
diff --git a/mod/settings.php b/mod/settings.php
index d886288409..589b2383a3 100644
--- a/mod/settings.php
+++ b/mod/settings.php
@@ -25,6 +25,7 @@ use Friendica\Model\User;
 use Friendica\Module\Login;
 use Friendica\Protocol\Email;
 use Friendica\Util\Network;
+use Friendica\Util\Strings;
 use Friendica\Util\Temporal;
 
 function get_theme_config_file($theme)
@@ -314,8 +315,8 @@ function settings_post(App $a)
 	if (($a->argc > 1) && ($a->argv[1] === 'display')) {
 		BaseModule::checkFormSecurityTokenRedirectOnError('/settings/display', 'settings_display');
 
-		$theme             = x($_POST, 'theme')             ? notags(trim($_POST['theme']))        : $a->user['theme'];
-		$mobile_theme      = x($_POST, 'mobile_theme')      ? notags(trim($_POST['mobile_theme'])) : '';
+		$theme             = x($_POST, 'theme')             ? Strings::removeTags(trim($_POST['theme']))        : $a->user['theme'];
+		$mobile_theme      = x($_POST, 'mobile_theme')      ? Strings::removeTags(trim($_POST['mobile_theme'])) : '';
 		$nosmile           = x($_POST, 'nosmile')           ? intval($_POST['nosmile'])            : 0;
 		$first_day_of_week = x($_POST, 'first_day_of_week') ? intval($_POST['first_day_of_week'])  : 0;
 		$noinfo            = x($_POST, 'noinfo')            ? intval($_POST['noinfo'])             : 0;
@@ -422,13 +423,13 @@ function settings_post(App $a)
 		}
 	}
 
-	$username         = ((x($_POST, 'username'))   ? notags(trim($_POST['username']))     : '');
-	$email            = ((x($_POST, 'email'))      ? notags(trim($_POST['email']))        : '');
-	$timezone         = ((x($_POST, 'timezone'))   ? notags(trim($_POST['timezone']))     : '');
-	$language         = ((x($_POST, 'language'))   ? notags(trim($_POST['language']))     : '');
+	$username         = ((x($_POST, 'username'))   ? Strings::removeTags(trim($_POST['username']))     : '');
+	$email            = ((x($_POST, 'email'))      ? Strings::removeTags(trim($_POST['email']))        : '');
+	$timezone         = ((x($_POST, 'timezone'))   ? Strings::removeTags(trim($_POST['timezone']))     : '');
+	$language         = ((x($_POST, 'language'))   ? Strings::removeTags(trim($_POST['language']))     : '');
 
-	$defloc           = ((x($_POST, 'defloc'))     ? notags(trim($_POST['defloc']))       : '');
-	$openid           = ((x($_POST, 'openid_url')) ? notags(trim($_POST['openid_url']))   : '');
+	$defloc           = ((x($_POST, 'defloc'))     ? Strings::removeTags(trim($_POST['defloc']))       : '');
+	$openid           = ((x($_POST, 'openid_url')) ? Strings::removeTags(trim($_POST['openid_url']))   : '');
 	$maxreq           = ((x($_POST, 'maxreq'))     ? intval($_POST['maxreq'])             : 0);
 	$expire           = ((x($_POST, 'expire'))     ? intval($_POST['expire'])             : 0);
 	$def_gid          = ((x($_POST, 'group-selection')) ? intval($_POST['group-selection']) : 0);
diff --git a/mod/subthread.php b/mod/subthread.php
index 425306b6f7..68fa0e7ea3 100644
--- a/mod/subthread.php
+++ b/mod/subthread.php
@@ -10,6 +10,7 @@ use Friendica\Core\System;
 use Friendica\Database\DBA;
 use Friendica\Model\Item;
 use Friendica\Util\Security;
+use Friendica\Util\Strings;
 use Friendica\Util\XML;
 
 require_once 'include/items.php';
@@ -22,7 +23,7 @@ function subthread_content(App $a) {
 
 	$activity = ACTIVITY_FOLLOW;
 
-	$item_id = (($a->argc > 1) ? notags(trim($a->argv[1])) : 0);
+	$item_id = (($a->argc > 1) ? Strings::removeTags(trim($a->argv[1])) : 0);
 
 	$condition = ["`parent` = ? OR `parent-uri` = ? AND `parent` = `id`", $item_id, $item_id];
 	$item = Item::selectFirst([], $condition);
diff --git a/mod/tagger.php b/mod/tagger.php
index dd859e61cd..c0eeb684ce 100644
--- a/mod/tagger.php
+++ b/mod/tagger.php
@@ -10,6 +10,7 @@ use Friendica\Core\System;
 use Friendica\Core\Worker;
 use Friendica\Database\DBA;
 use Friendica\Model\Item;
+use Friendica\Util\Strings;
 use Friendica\Util\XML;
 
 require_once 'include/items.php';
@@ -20,7 +21,7 @@ function tagger_content(App $a) {
 		return;
 	}
 
-	$term = notags(trim($_GET['term']));
+	$term = Strings::removeTags(trim($_GET['term']));
 	// no commas allowed
 	$term = str_replace([',',' '],['','_'],$term);
 
@@ -28,7 +29,7 @@ function tagger_content(App $a) {
 		return;
 	}
 
-	$item_id = (($a->argc > 1) ? notags(trim($a->argv[1])) : 0);
+	$item_id = (($a->argc > 1) ? Strings::removeTags(trim($a->argv[1])) : 0);
 
 	Logger::log('tagger: tag ' . $term . ' item ' . $item_id);
 
diff --git a/mod/tagrm.php b/mod/tagrm.php
index 2678748de5..266dbfa3c8 100644
--- a/mod/tagrm.php
+++ b/mod/tagrm.php
@@ -9,6 +9,7 @@ use Friendica\Core\L10n;
 use Friendica\Database\DBA;
 use Friendica\Model\Item;
 use Friendica\Model\Term;
+use Friendica\Util\Strings;
 
 function tagrm_post(App $a)
 {
@@ -22,7 +23,7 @@ function tagrm_post(App $a)
 
 	$tags = [];
 	foreach (defaults($_POST, 'tag', []) as $tag) {
-		$tags[] = hex2bin(notags(trim($tag)));
+		$tags[] = hex2bin(Strings::removeTags(trim($tag)));
 	}
 
 	$item_id = defaults($_POST,'item', 0);
@@ -73,7 +74,7 @@ function tagrm_content(App $a)
 	}
 
 	if ($a->argc == 3) {
-		update_tags($a->argv[1], [notags(trim(hex2bin($a->argv[2])))]);
+		update_tags($a->argv[1], [Strings::removeTags(trim(hex2bin($a->argv[2])))]);
 		$a->internalRedirect($_SESSION['photo_return']);
 	}
 
diff --git a/mod/unfollow.php b/mod/unfollow.php
index 372364810e..e2ee312f24 100644
--- a/mod/unfollow.php
+++ b/mod/unfollow.php
@@ -12,6 +12,7 @@ use Friendica\Database\DBA;
 use Friendica\Model\Contact;
 use Friendica\Model\Profile;
 use Friendica\Model\User;
+use Friendica\Util\Strings;
 
 function unfollow_post(App $a)
 {
@@ -24,7 +25,7 @@ function unfollow_post(App $a)
 	}
 
 	$uid = local_user();
-	$url = notags(trim(defaults($_REQUEST, 'url', '')));
+	$url = Strings::removeTags(trim(defaults($_REQUEST, 'url', '')));
 
 	$condition = ["`uid` = ? AND (`rel` = ? OR `rel` = ?) AND (`nurl` = ? OR `alias` = ? OR `alias` = ?)",
 		$uid, Contact::SHARING, Contact::FRIEND, normalise_link($url),
@@ -79,7 +80,7 @@ function unfollow_content(App $a)
 	}
 
 	$uid = local_user();
-	$url = notags(trim($_REQUEST['url']));
+	$url = Strings::removeTags(trim($_REQUEST['url']));
 
 	$condition = ["`uid` = ? AND (`rel` = ? OR `rel` = ?) AND (`nurl` = ? OR `alias` = ? OR `alias` = ?)",
 		local_user(), Contact::SHARING, Contact::FRIEND, normalise_link($url),
diff --git a/mod/wall_upload.php b/mod/wall_upload.php
index 84e40d3b56..c093d28e3a 100644
--- a/mod/wall_upload.php
+++ b/mod/wall_upload.php
@@ -17,13 +17,14 @@ use Friendica\Database\DBA;
 use Friendica\Model\Contact;
 use Friendica\Model\Photo;
 use Friendica\Object\Image;
+use Friendica\Util\Strings;
 
 function wall_upload_post(App $a, $desktopmode = true)
 {
 	Logger::log("wall upload: starting new upload", Logger::DEBUG);
 
 	$r_json = (x($_GET, 'response') && $_GET['response'] == 'json');
-	$album = (x($_GET, 'album') ? notags(trim($_GET['album'])) : '');
+	$album = (x($_GET, 'album') ? Strings::removeTags(trim($_GET['album'])) : '');
 
 	if ($a->argc > 1) {
 		if (!x($_FILES, 'media')) {
diff --git a/mod/wallmessage.php b/mod/wallmessage.php
index 78cdd5a55a..aa5186452d 100644
--- a/mod/wallmessage.php
+++ b/mod/wallmessage.php
@@ -10,6 +10,7 @@ use Friendica\Core\System;
 use Friendica\Database\DBA;
 use Friendica\Model\Mail;
 use Friendica\Model\Profile;
+use Friendica\Util\Strings;
 
 function wallmessage_post(App $a) {
 
@@ -19,10 +20,10 @@ function wallmessage_post(App $a) {
 		return;
 	}
 
-	$subject   = ((x($_REQUEST,'subject'))   ? notags(trim($_REQUEST['subject']))   : '');
+	$subject   = ((x($_REQUEST,'subject'))   ? Strings::removeTags(trim($_REQUEST['subject']))   : '');
 	$body      = ((x($_REQUEST,'body'))      ? escape_tags(trim($_REQUEST['body'])) : '');
 
-	$recipient = (($a->argc > 1) ? notags($a->argv[1]) : '');
+	$recipient = (($a->argc > 1) ? Strings::removeTags($a->argv[1]) : '');
 	if ((! $recipient) || (! $body)) {
 		return;
 	}
diff --git a/mod/xrd.php b/mod/xrd.php
index 83f069d14a..657a0f0ca9 100644
--- a/mod/xrd.php
+++ b/mod/xrd.php
@@ -9,6 +9,7 @@ use Friendica\Core\Renderer;
 use Friendica\Core\System;
 use Friendica\Database\DBA;
 use Friendica\Protocol\Salmon;
+use Friendica\Util\Strings;
 
 function xrd_init(App $a)
 {
@@ -17,7 +18,7 @@ function xrd_init(App $a)
 			System::httpExit(404);
 		}
 
-		$uri = urldecode(notags(trim($_GET['uri'])));
+		$uri = urldecode(Strings::removeTags(trim($_GET['uri'])));
 		if (defaults($_SERVER, 'HTTP_ACCEPT', '') == 'application/jrd+json') {
 			$mode = 'json';
 		} else {
@@ -28,7 +29,7 @@ function xrd_init(App $a)
 			System::httpExit(404);
 		}
 
-		$uri = urldecode(notags(trim($_GET['resource'])));
+		$uri = urldecode(Strings::removeTags(trim($_GET['resource'])));
 		if (defaults($_SERVER, 'HTTP_ACCEPT', '') == 'application/xrd+xml') {
 			$mode = 'xml';
 		} else {
diff --git a/src/Model/Item.php b/src/Model/Item.php
index 35dfb7264c..4790f9f6d7 100644
--- a/src/Model/Item.php
+++ b/src/Model/Item.php
@@ -1150,7 +1150,7 @@ class Item extends BaseObject
 	private static function guid($item, $notify)
 	{
 		if (!empty($item['guid'])) {
-			return notags(trim($item['guid']));
+			return Strings::removeTags(trim($item['guid']));
 		}
 
 		if ($notify) {
@@ -1265,7 +1265,7 @@ class Item extends BaseObject
 		}
 
 		$item['guid'] = self::guid($item, $notify);
-		$item['uri'] = notags(trim(defaults($item, 'uri', self::newURI($item['uid'], $item['guid']))));
+		$item['uri'] = Strings::removeTags(trim(defaults($item, 'uri', self::newURI($item['uid'], $item['guid']))));
 
 		// Store URI data
 		$item['uri-id'] = ItemURI::insert(['uri' => $item['uri'], 'guid' => $item['guid']]);
diff --git a/src/Model/Profile.php b/src/Model/Profile.php
index 95a6bd35bc..b6a1e40a4e 100644
--- a/src/Model/Profile.php
+++ b/src/Model/Profile.php
@@ -25,6 +25,7 @@ use Friendica\Protocol\Diaspora;
 use Friendica\Util\DateTimeFormat;
 use Friendica\Util\Network;
 use Friendica\Util\Proxy as ProxyUtils;
+use Friendica\Util\Strings;
 use Friendica\Util\Temporal;
 
 require_once 'include/dba.php';
@@ -881,7 +882,7 @@ class Profile
 
 		$tab = false;
 		if (x($_GET, 'tab')) {
-			$tab = notags(trim($_GET['tab']));
+			$tab = Strings::removeTags(trim($_GET['tab']));
 		}
 
 		$url = System::baseUrl() . '/profile/' . $nickname;
diff --git a/src/Model/User.php b/src/Model/User.php
index a5db34bb44..e52ff319dd 100644
--- a/src/Model/User.php
+++ b/src/Model/User.php
@@ -20,6 +20,7 @@ use Friendica\Object\Image;
 use Friendica\Util\Crypto;
 use Friendica\Util\DateTimeFormat;
 use Friendica\Util\Network;
+use Friendica\Util\Strings;
 use LightOpenID;
 
 require_once 'boot.php';
@@ -401,18 +402,18 @@ class User
 		$using_invites = Config::get('system', 'invitation_only');
 		$num_invites   = Config::get('system', 'number_invites');
 
-		$invite_id  = !empty($data['invite_id'])  ? notags(trim($data['invite_id']))  : '';
-		$username   = !empty($data['username'])   ? notags(trim($data['username']))   : '';
-		$nickname   = !empty($data['nickname'])   ? notags(trim($data['nickname']))   : '';
-		$email      = !empty($data['email'])      ? notags(trim($data['email']))      : '';
-		$openid_url = !empty($data['openid_url']) ? notags(trim($data['openid_url'])) : '';
-		$photo      = !empty($data['photo'])      ? notags(trim($data['photo']))      : '';
+		$invite_id  = !empty($data['invite_id'])  ? Strings::removeTags(trim($data['invite_id']))  : '';
+		$username   = !empty($data['username'])   ? Strings::removeTags(trim($data['username']))   : '';
+		$nickname   = !empty($data['nickname'])   ? Strings::removeTags(trim($data['nickname']))   : '';
+		$email      = !empty($data['email'])      ? Strings::removeTags(trim($data['email']))      : '';
+		$openid_url = !empty($data['openid_url']) ? Strings::removeTags(trim($data['openid_url'])) : '';
+		$photo      = !empty($data['photo'])      ? Strings::removeTags(trim($data['photo']))      : '';
 		$password   = !empty($data['password'])   ? trim($data['password'])           : '';
 		$password1  = !empty($data['password1'])  ? trim($data['password1'])          : '';
 		$confirm    = !empty($data['confirm'])    ? trim($data['confirm'])            : '';
 		$blocked    = !empty($data['blocked'])    ? intval($data['blocked'])          : 0;
 		$verified   = !empty($data['verified'])   ? intval($data['verified'])         : 0;
-		$language   = !empty($data['language'])   ? notags(trim($data['language']))   : 'en';
+		$language   = !empty($data['language'])   ? Strings::removeTags(trim($data['language']))   : 'en';
 
 		$publish = !empty($data['profile_publish_reg']) && intval($data['profile_publish_reg']) ? 1 : 0;
 		$netpublish = strlen(Config::get('system', 'directory')) ? $publish : 0;
diff --git a/src/Module/Contact.php b/src/Module/Contact.php
index db30075984..c25665f247 100644
--- a/src/Module/Contact.php
+++ b/src/Module/Contact.php
@@ -22,6 +22,7 @@ use Friendica\Module\Login;
 use Friendica\Network\Probe;
 use Friendica\Util\DateTimeFormat;
 use Friendica\Util\Proxy as ProxyUtils;
+use Friendica\Util\Strings;
 
 /**
  *  Manages and show Contacts and their content
@@ -601,7 +602,7 @@ class Contact extends BaseModule
 				'$lbl_vis2'       => L10n::t('Please choose the profile you would like to display to %s when viewing your profile securely.', $contact['name']),
 				'$lbl_info1'      => $lbl_info1,
 				'$lbl_info2'      => L10n::t('Their personal note'),
-				'$reason'         => trim(notags($contact['reason'])),
+				'$reason'         => trim(Strings::removeTags($contact['reason'])),
 				'$infedit'        => L10n::t('Edit contact notes'),
 				'$common_link'    => 'common/loc/' . local_user() . '/' . $contact['id'],
 				'$relation_text'  => $relation_text,
@@ -694,8 +695,8 @@ class Contact extends BaseModule
 
 		$sql_extra .= sprintf(" AND `network` != '%s' ", Protocol::PHANTOM);
 
-		$search = notags(trim(defaults($_GET, 'search', '')));
-		$nets   = notags(trim(defaults($_GET, 'nets'  , '')));
+		$search = Strings::removeTags(trim(defaults($_GET, 'search', '')));
+		$nets   = Strings::removeTags(trim(defaults($_GET, 'nets'  , '')));
 
 		$tabs = [
 			[
diff --git a/src/Module/Install.php b/src/Module/Install.php
index 2defe24adf..f6e5fc6c5f 100644
--- a/src/Module/Install.php
+++ b/src/Module/Install.php
@@ -9,6 +9,7 @@ use Friendica\Database\DBStructure;
 use Friendica\Core;
 use Friendica\Core\L10n;
 use Friendica\Core\Renderer;
+use Friendica\Util\Strings;
 use Friendica\Util\Temporal;
 
 class Install extends BaseModule
@@ -70,10 +71,10 @@ class Install extends BaseModule
 				break;
 
 			case self::SITE_SETTINGS:
-				$dbhost  = notags(trim(defaults($_POST, 'dbhost', Core\Installer::DEFAULT_HOST)));
-				$dbuser  = notags(trim(defaults($_POST, 'dbuser', '')));
-				$dbpass  = notags(trim(defaults($_POST, 'dbpass', '')));
-				$dbdata  = notags(trim(defaults($_POST, 'dbdata', '')));
+				$dbhost  = Strings::removeTags(trim(defaults($_POST, 'dbhost', Core\Installer::DEFAULT_HOST)));
+				$dbuser  = Strings::removeTags(trim(defaults($_POST, 'dbuser', '')));
+				$dbpass  = Strings::removeTags(trim(defaults($_POST, 'dbpass', '')));
+				$dbdata  = Strings::removeTags(trim(defaults($_POST, 'dbdata', '')));
 
 				// If we cannot connect to the database, return to the previous step
 				if (!self::$installer->checkDB($dbhost, $dbuser, $dbpass, $dbdata)) {
@@ -84,13 +85,13 @@ class Install extends BaseModule
 
 			case self::FINISHED:
 				$urlpath   = $a->getURLPath();
-				$dbhost    = notags(trim(defaults($_POST, 'dbhost', Core\Installer::DEFAULT_HOST)));
-				$dbuser    = notags(trim(defaults($_POST, 'dbuser', '')));
-				$dbpass    = notags(trim(defaults($_POST, 'dbpass', '')));
-				$dbdata    = notags(trim(defaults($_POST, 'dbdata', '')));
-				$timezone  = notags(trim(defaults($_POST, 'timezone', Core\Installer::DEFAULT_TZ)));
-				$language  = notags(trim(defaults($_POST, 'language', Core\Installer::DEFAULT_LANG)));
-				$adminmail = notags(trim(defaults($_POST, 'adminmail', '')));
+				$dbhost    = Strings::removeTags(trim(defaults($_POST, 'dbhost', Core\Installer::DEFAULT_HOST)));
+				$dbuser    = Strings::removeTags(trim(defaults($_POST, 'dbuser', '')));
+				$dbpass    = Strings::removeTags(trim(defaults($_POST, 'dbpass', '')));
+				$dbdata    = Strings::removeTags(trim(defaults($_POST, 'dbdata', '')));
+				$timezone  = Strings::removeTags(trim(defaults($_POST, 'timezone', Core\Installer::DEFAULT_TZ)));
+				$language  = Strings::removeTags(trim(defaults($_POST, 'language', Core\Installer::DEFAULT_LANG)));
+				$adminmail = Strings::removeTags(trim(defaults($_POST, 'adminmail', '')));
 
 				// If we cannot connect to the database, return to the Database config wizard
 				if (!self::$installer->checkDB($dbhost, $dbuser, $dbpass, $dbdata)) {
@@ -139,12 +140,12 @@ class Install extends BaseModule
 				break;
 
 			case self::DATABASE_CONFIG:
-				$dbhost    = notags(trim(defaults($_POST, 'dbhost'   , Core\Installer::DEFAULT_HOST)));
-				$dbuser    = notags(trim(defaults($_POST, 'dbuser'   , ''                          )));
-				$dbpass    = notags(trim(defaults($_POST, 'dbpass'   , ''                          )));
-				$dbdata    = notags(trim(defaults($_POST, 'dbdata'   , ''                          )));
-				$phpath    = notags(trim(defaults($_POST, 'phpath'   , ''                          )));
-				$adminmail = notags(trim(defaults($_POST, 'adminmail', ''                          )));
+				$dbhost    = Strings::removeTags(trim(defaults($_POST, 'dbhost'   , Core\Installer::DEFAULT_HOST)));
+				$dbuser    = Strings::removeTags(trim(defaults($_POST, 'dbuser'   , ''                          )));
+				$dbpass    = Strings::removeTags(trim(defaults($_POST, 'dbpass'   , ''                          )));
+				$dbdata    = Strings::removeTags(trim(defaults($_POST, 'dbdata'   , ''                          )));
+				$phpath    = Strings::removeTags(trim(defaults($_POST, 'phpath'   , ''                          )));
+				$adminmail = Strings::removeTags(trim(defaults($_POST, 'adminmail', ''                          )));
 
 				$tpl = Renderer::getMarkupTemplate('install_db.tpl');
 				$output .= Renderer::replaceMacros($tpl, [
@@ -190,13 +191,13 @@ class Install extends BaseModule
 				break;
 
 			case self::SITE_SETTINGS:
-				$dbhost = notags(trim(defaults($_POST, 'dbhost', Core\Installer::DEFAULT_HOST)));
-				$dbuser = notags(trim(defaults($_POST, 'dbuser', ''                          )));
-				$dbpass = notags(trim(defaults($_POST, 'dbpass', ''                          )));
-				$dbdata = notags(trim(defaults($_POST, 'dbdata', ''                          )));
-				$phpath = notags(trim(defaults($_POST, 'phpath', ''                          )));
+				$dbhost = Strings::removeTags(trim(defaults($_POST, 'dbhost', Core\Installer::DEFAULT_HOST)));
+				$dbuser = Strings::removeTags(trim(defaults($_POST, 'dbuser', ''                          )));
+				$dbpass = Strings::removeTags(trim(defaults($_POST, 'dbpass', ''                          )));
+				$dbdata = Strings::removeTags(trim(defaults($_POST, 'dbdata', ''                          )));
+				$phpath = Strings::removeTags(trim(defaults($_POST, 'phpath', ''                          )));
 
-				$adminmail = notags(trim(defaults($_POST, 'adminmail', '')));
+				$adminmail = Strings::removeTags(trim(defaults($_POST, 'adminmail', '')));
 
 				$timezone = defaults($_POST, 'timezone', Core\Installer::DEFAULT_TZ);
 				/* Installed langs */
diff --git a/src/Module/Login.php b/src/Module/Login.php
index 751d4d4cce..7cf1bd8787 100644
--- a/src/Module/Login.php
+++ b/src/Module/Login.php
@@ -17,6 +17,7 @@ use Friendica\Database\DBA;
 use Friendica\Model\User;
 use Friendica\Util\DateTimeFormat;
 use Friendica\Util\Network;
+use Friendica\Util\Strings;
 use LightOpenID;
 
 require_once 'boot.php';
@@ -148,7 +149,7 @@ class Login extends BaseModule
 				);
 			}
 		} catch (Exception $e) {
-			Logger::log('authenticate: failed login attempt: ' . notags($username) . ' from IP ' . $_SERVER['REMOTE_ADDR']);
+			Logger::log('authenticate: failed login attempt: ' . Strings::removeTags($username) . ' from IP ' . $_SERVER['REMOTE_ADDR']);
 			info('Login failed. Please check your credentials.' . EOL);
 			$a->internalRedirect();
 		}
diff --git a/src/Network/Probe.php b/src/Network/Probe.php
index a9a7a93ab9..efd58e2b36 100644
--- a/src/Network/Probe.php
+++ b/src/Network/Probe.php
@@ -1674,7 +1674,7 @@ class Probe
 						}
 					}
 
-					$data["name"] = notags($data["name"]);
+					$data["name"] = Strings::removeTags($data["name"]);
 				}
 			}
 		}
diff --git a/src/Protocol/DFRN.php b/src/Protocol/DFRN.php
index c9ad69cc10..a6efeb76a2 100644
--- a/src/Protocol/DFRN.php
+++ b/src/Protocol/DFRN.php
@@ -2494,7 +2494,7 @@ class DFRN
 		$item["body"] = XML::getFirstNodeValue($xpath, "dfrn:env/text()", $entry);
 		$item["body"] = str_replace([' ',"\t","\r","\n"], ['','','',''], $item["body"]);
 		// make sure nobody is trying to sneak some html tags by us
-		$item["body"] = notags(base64url_decode($item["body"]));
+		$item["body"] = Strings::removeTags(base64url_decode($item["body"]));
 
 		$item["body"] = BBCode::limitBodySize($item["body"]);
 
diff --git a/src/Protocol/Diaspora.php b/src/Protocol/Diaspora.php
index 8fc17f97d1..b552a415f2 100644
--- a/src/Protocol/Diaspora.php
+++ b/src/Protocol/Diaspora.php
@@ -1506,9 +1506,9 @@ class Diaspora
 	 */
 	private static function receiveAccountMigration(array $importer, $data)
 	{
-		$old_handle = notags(XML::unescape($data->author));
-		$new_handle = notags(XML::unescape($data->profile->author));
-		$signature = notags(XML::unescape($data->signature));
+		$old_handle = Strings::removeTags(XML::unescape($data->author));
+		$new_handle = Strings::removeTags(XML::unescape($data->profile->author));
+		$signature = Strings::removeTags(XML::unescape($data->signature));
 
 		$contact = self::contactByHandle($importer["uid"], $old_handle);
 		if (!$contact) {
@@ -1566,7 +1566,7 @@ class Diaspora
 	 */
 	private static function receiveAccountDeletion($data)
 	{
-		$author = notags(XML::unescape($data->author));
+		$author = Strings::removeTags(XML::unescape($data->author));
 
 		$contacts = DBA::select('contact', ['id'], ['addr' => $author]);
 		while ($contact = DBA::fetch($contacts)) {
@@ -1657,19 +1657,19 @@ class Diaspora
 	 */
 	private static function receiveComment(array $importer, $sender, $data, $xml)
 	{
-		$author = notags(XML::unescape($data->author));
-		$guid = notags(XML::unescape($data->guid));
-		$parent_guid = notags(XML::unescape($data->parent_guid));
+		$author = Strings::removeTags(XML::unescape($data->author));
+		$guid = Strings::removeTags(XML::unescape($data->guid));
+		$parent_guid = Strings::removeTags(XML::unescape($data->parent_guid));
 		$text = XML::unescape($data->text);
 
 		if (isset($data->created_at)) {
-			$created_at = DateTimeFormat::utc(notags(XML::unescape($data->created_at)));
+			$created_at = DateTimeFormat::utc(Strings::removeTags(XML::unescape($data->created_at)));
 		} else {
 			$created_at = DateTimeFormat::utcNow();
 		}
 
 		if (isset($data->thread_parent_guid)) {
-			$thread_parent_guid = notags(XML::unescape($data->thread_parent_guid));
+			$thread_parent_guid = Strings::removeTags(XML::unescape($data->thread_parent_guid));
 			$thr_uri = self::getUriFromGuid("", $thread_parent_guid, true);
 		} else {
 			$thr_uri = "";
@@ -1774,24 +1774,24 @@ class Diaspora
 	 */
 	private static function receiveConversationMessage(array $importer, array $contact, $data, $msg, $mesg, $conversation)
 	{
-		$author = notags(XML::unescape($data->author));
-		$guid = notags(XML::unescape($data->guid));
-		$subject = notags(XML::unescape($data->subject));
+		$author = Strings::removeTags(XML::unescape($data->author));
+		$guid = Strings::removeTags(XML::unescape($data->guid));
+		$subject = Strings::removeTags(XML::unescape($data->subject));
 
 		// "diaspora_handle" is the element name from the old version
 		// "author" is the element name from the new version
 		if ($mesg->author) {
-			$msg_author = notags(XML::unescape($mesg->author));
+			$msg_author = Strings::removeTags(XML::unescape($mesg->author));
 		} elseif ($mesg->diaspora_handle) {
-			$msg_author = notags(XML::unescape($mesg->diaspora_handle));
+			$msg_author = Strings::removeTags(XML::unescape($mesg->diaspora_handle));
 		} else {
 			return false;
 		}
 
-		$msg_guid = notags(XML::unescape($mesg->guid));
-		$msg_conversation_guid = notags(XML::unescape($mesg->conversation_guid));
+		$msg_guid = Strings::removeTags(XML::unescape($mesg->guid));
+		$msg_conversation_guid = Strings::removeTags(XML::unescape($mesg->conversation_guid));
 		$msg_text = XML::unescape($mesg->text);
-		$msg_created_at = DateTimeFormat::utc(notags(XML::unescape($mesg->created_at)));
+		$msg_created_at = DateTimeFormat::utc(Strings::removeTags(XML::unescape($mesg->created_at)));
 
 		if ($msg_conversation_guid != $guid) {
 			Logger::log("message conversation guid does not belong to the current conversation.");
@@ -1862,11 +1862,11 @@ class Diaspora
 	 */
 	private static function receiveConversation(array $importer, $msg, $data)
 	{
-		$author = notags(XML::unescape($data->author));
-		$guid = notags(XML::unescape($data->guid));
-		$subject = notags(XML::unescape($data->subject));
-		$created_at = DateTimeFormat::utc(notags(XML::unescape($data->created_at)));
-		$participants = notags(XML::unescape($data->participants));
+		$author = Strings::removeTags(XML::unescape($data->author));
+		$guid = Strings::removeTags(XML::unescape($data->guid));
+		$subject = Strings::removeTags(XML::unescape($data->subject));
+		$created_at = DateTimeFormat::utc(Strings::removeTags(XML::unescape($data->created_at)));
+		$participants = Strings::removeTags(XML::unescape($data->participants));
 
 		$messages = $data->message;
 
@@ -1920,11 +1920,11 @@ class Diaspora
 	 */
 	private static function receiveLike(array $importer, $sender, $data)
 	{
-		$author = notags(XML::unescape($data->author));
-		$guid = notags(XML::unescape($data->guid));
-		$parent_guid = notags(XML::unescape($data->parent_guid));
-		$parent_type = notags(XML::unescape($data->parent_type));
-		$positive = notags(XML::unescape($data->positive));
+		$author = Strings::removeTags(XML::unescape($data->author));
+		$guid = Strings::removeTags(XML::unescape($data->guid));
+		$parent_guid = Strings::removeTags(XML::unescape($data->parent_guid));
+		$parent_type = Strings::removeTags(XML::unescape($data->parent_type));
+		$positive = Strings::removeTags(XML::unescape($data->positive));
 
 		// likes on comments aren't supported by Diaspora - only on posts
 		// But maybe this will be supported in the future, so we will accept it.
@@ -2029,11 +2029,11 @@ class Diaspora
 	 */
 	private static function receiveMessage(array $importer, $data)
 	{
-		$author = notags(XML::unescape($data->author));
-		$guid = notags(XML::unescape($data->guid));
-		$conversation_guid = notags(XML::unescape($data->conversation_guid));
+		$author = Strings::removeTags(XML::unescape($data->author));
+		$guid = Strings::removeTags(XML::unescape($data->guid));
+		$conversation_guid = Strings::removeTags(XML::unescape($data->conversation_guid));
 		$text = XML::unescape($data->text);
-		$created_at = DateTimeFormat::utc(notags(XML::unescape($data->created_at)));
+		$created_at = DateTimeFormat::utc(Strings::removeTags(XML::unescape($data->created_at)));
 
 		$contact = self::allowedContactByHandle($importer, $author, true);
 		if (!$contact) {
@@ -2104,8 +2104,8 @@ class Diaspora
 	 */
 	private static function receiveParticipation(array $importer, $data)
 	{
-		$author = strtolower(notags(XML::unescape($data->author)));
-		$parent_guid = notags(XML::unescape($data->parent_guid));
+		$author = strtolower(Strings::removeTags(XML::unescape($data->author)));
+		$parent_guid = Strings::removeTags(XML::unescape($data->parent_guid));
 
 		$contact_id = Contact::getIdForURL($author);
 		if (!$contact_id) {
@@ -2197,7 +2197,7 @@ class Diaspora
 	 */
 	private static function receiveProfile(array $importer, $data)
 	{
-		$author = strtolower(notags(XML::unescape($data->author)));
+		$author = strtolower(Strings::removeTags(XML::unescape($data->author)));
 
 		$contact = self::contactByHandle($importer["uid"], $author);
 		if (!$contact) {
@@ -2574,13 +2574,13 @@ class Diaspora
 	 */
 	private static function receiveReshare(array $importer, $data, $xml)
 	{
-		$author = notags(XML::unescape($data->author));
-		$guid = notags(XML::unescape($data->guid));
-		$created_at = DateTimeFormat::utc(notags(XML::unescape($data->created_at)));
-		$root_author = notags(XML::unescape($data->root_author));
-		$root_guid = notags(XML::unescape($data->root_guid));
+		$author = Strings::removeTags(XML::unescape($data->author));
+		$guid = Strings::removeTags(XML::unescape($data->guid));
+		$created_at = DateTimeFormat::utc(Strings::removeTags(XML::unescape($data->created_at)));
+		$root_author = Strings::removeTags(XML::unescape($data->root_author));
+		$root_guid = Strings::removeTags(XML::unescape($data->root_guid));
 		/// @todo handle unprocessed property "provider_display_name"
-		$public = notags(XML::unescape($data->public));
+		$public = Strings::removeTags(XML::unescape($data->public));
 
 		$contact = self::allowedContactByHandle($importer, $author, false);
 		if (!$contact) {
@@ -2666,9 +2666,9 @@ class Diaspora
 	 */
 	private static function itemRetraction(array $importer, array $contact, $data)
 	{
-		$author = notags(XML::unescape($data->author));
-		$target_guid = notags(XML::unescape($data->target_guid));
-		$target_type = notags(XML::unescape($data->target_type));
+		$author = Strings::removeTags(XML::unescape($data->author));
+		$target_guid = Strings::removeTags(XML::unescape($data->target_guid));
+		$target_type = Strings::removeTags(XML::unescape($data->target_type));
 
 		$person = self::personByHandle($author);
 		if (!is_array($person)) {
@@ -2730,7 +2730,7 @@ class Diaspora
 	 */
 	private static function receiveRetraction(array $importer, $sender, $data)
 	{
-		$target_type = notags(XML::unescape($data->target_type));
+		$target_type = Strings::removeTags(XML::unescape($data->target_type));
 
 		$contact = self::contactByHandle($importer["uid"], $sender);
 		if (!$contact && (in_array($target_type, ["Contact", "Person"]))) {
@@ -2775,12 +2775,12 @@ class Diaspora
 	 */
 	private static function receiveStatusMessage(array $importer, SimpleXMLElement $data, $xml)
 	{
-		$author = notags(XML::unescape($data->author));
-		$guid = notags(XML::unescape($data->guid));
-		$created_at = DateTimeFormat::utc(notags(XML::unescape($data->created_at)));
-		$public = notags(XML::unescape($data->public));
+		$author = Strings::removeTags(XML::unescape($data->author));
+		$guid = Strings::removeTags(XML::unescape($data->guid));
+		$created_at = DateTimeFormat::utc(Strings::removeTags(XML::unescape($data->created_at)));
+		$public = Strings::removeTags(XML::unescape($data->public));
 		$text = XML::unescape($data->text);
-		$provider_display_name = notags(XML::unescape($data->provider_display_name));
+		$provider_display_name = Strings::removeTags(XML::unescape($data->provider_display_name));
 
 		$contact = self::allowedContactByHandle($importer, $author, false);
 		if (!$contact) {
@@ -2795,7 +2795,7 @@ class Diaspora
 		$address = [];
 		if ($data->location) {
 			foreach ($data->location->children() as $fieldname => $data) {
-				$address[$fieldname] = notags(XML::unescape($data));
+				$address[$fieldname] = Strings::removeTags(XML::unescape($data));
 			}
 		}
 
diff --git a/src/Util/Strings.php b/src/Util/Strings.php
index ceb1a946a1..f536e60a12 100644
--- a/src/Util/Strings.php
+++ b/src/Util/Strings.php
@@ -44,7 +44,7 @@ class Strings
      * @param string $string Input string
      * @return string Filtered string
      */
-    public static function removeTags($string) // notags()
+    public static function removeTags($string)
     {
         return str_replace(["<", ">"], ['[', ']'], $string);
     }
diff --git a/src/Worker/OnePoll.php b/src/Worker/OnePoll.php
index 77745b8070..5de6df174f 100644
--- a/src/Worker/OnePoll.php
+++ b/src/Worker/OnePoll.php
@@ -18,6 +18,7 @@ use Friendica\Protocol\Email;
 use Friendica\Protocol\PortableContact;
 use Friendica\Util\DateTimeFormat;
 use Friendica\Util\Network;
+use Friendica\Util\Strings;
 use Friendica\Util\XML;
 
 require_once 'include/dba.php';
@@ -474,9 +475,9 @@ class OnePoll
 									$datarray['title'] .= $subpart->text;
 								}
 							}
-							$datarray['title'] = notags(trim($datarray['title']));
+							$datarray['title'] = Strings::removeTags(trim($datarray['title']));
 
-							//$datarray['title'] = notags(trim($meta->subject));
+							//$datarray['title'] = Strings::removeTags(trim($meta->subject));
 							$datarray['created'] = DateTimeFormat::utc($meta->date);
 
 							// Is it a reply?
diff --git a/tests/include/TextTest.php b/tests/include/TextTest.php
index 1422ee2ae2..89e1dfcbdb 100644
--- a/tests/include/TextTest.php
+++ b/tests/include/TextTest.php
@@ -239,7 +239,7 @@ class TextTest extends TestCase
 	{
 		$invalidstring='<submit type="button" onclick="alert(\'failed!\');" />';
 
-		$validstring=notags($invalidstring);
+		$validstring = Friendica\Util\Strings::removeTags($invalidstring);
 		$escapedString=escape_tags($invalidstring);
 
 		$this->assertEquals('[submit type="button" onclick="alert(\'failed!\');" /]', $validstring);
diff --git a/view/theme/frio/theme.php b/view/theme/frio/theme.php
index c7d38baeb9..411e143611 100644
--- a/view/theme/frio/theme.php
+++ b/view/theme/frio/theme.php
@@ -20,6 +20,7 @@ use Friendica\Core\System;
 use Friendica\Database\DBA;
 use Friendica\Model;
 use Friendica\Module;
+use Friendica\Util\Strings;
 
 $frio = 'view/theme/frio';
 
@@ -300,7 +301,7 @@ function frio_remote_nav($a, &$nav)
  */
 function frio_acl_lookup(App $a, &$results)
 {
-	$nets = x($_GET, 'nets') ? notags(trim($_GET['nets'])) : '';
+	$nets = x($_GET, 'nets') ? Strings::removeTags(trim($_GET['nets'])) : '';
 
 	// we introduce a new search type, r should do the same query like it's
 	// done in /src/Module/Contact.php for connections