diff --git a/src/Content/OEmbed.php b/src/Content/OEmbed.php
index 7553cd9f81..562febdaf9 100644
--- a/src/Content/OEmbed.php
+++ b/src/Content/OEmbed.php
@@ -316,7 +316,7 @@ class OEmbed
 		if ($stopoembed == true) {
 			return preg_replace("/\[embed\](.+?)\[\/embed\]/is", "<!-- oembed $1 --><i>" . DI::l10n()->t('Embedding disabled') . " : $1</i><!-- /oembed $1 -->", $text);
 		}
-		return preg_replace_callback("/\[embed\](.+?)\[\/embed\]/is", ['self', 'replaceCallback'], $text);
+		return preg_replace_callback("/\[embed\](.+?)\[\/embed\]/is", [self::class, 'replaceCallback'], $text);
 	}
 
 	/**
diff --git a/src/Content/Smilies.php b/src/Content/Smilies.php
index 5ebb5b64e8..c51d9b3305 100644
--- a/src/Content/Smilies.php
+++ b/src/Content/Smilies.php
@@ -218,8 +218,8 @@ class Smilies
 			return $text;
 		}
 
-		$text = preg_replace_callback('/<(pre)>(.*?)<\/pre>/ism', 'self::encode', $text);
-		$text = preg_replace_callback('/<(code)>(.*?)<\/code>/ism', 'self::encode', $text);
+		$text = preg_replace_callback('/<(pre)>(.*?)<\/pre>/ism', [self::class, 'encode'], $text);
+		$text = preg_replace_callback('/<(code)>(.*?)<\/code>/ism', [self::class, 'encode'], $text);
 
 		if ($no_images) {
 			$cleaned = ['texts' => [], 'icons' => []];
@@ -233,11 +233,11 @@ class Smilies
 			$smilies = $cleaned;
 		}
 
-		$text = preg_replace_callback('/&lt;(3+)/', 'self::heartReplaceCallback', $text);
+		$text = preg_replace_callback('/&lt;(3+)/', [self::class, 'heartReplaceCallback'], $text);
 		$text = self::strOrigReplace($smilies['texts'], $smilies['icons'], $text);
 
-		$text = preg_replace_callback('/<(code)>(.*?)<\/code>/ism', 'self::decode', $text);
-		$text = preg_replace_callback('/<(pre)>(.*?)<\/pre>/ism', 'self::decode', $text);
+		$text = preg_replace_callback('/<(code)>(.*?)<\/code>/ism', [self::class, 'decode'], $text);
+		$text = preg_replace_callback('/<(pre)>(.*?)<\/pre>/ism', [self::class, 'decode'], $text);
 
 		return $text;
 	}
diff --git a/src/Content/Text/BBCode.php b/src/Content/Text/BBCode.php
index f65eeeee2c..e95ed06759 100644
--- a/src/Content/Text/BBCode.php
+++ b/src/Content/Text/BBCode.php
@@ -1415,8 +1415,8 @@ class BBCode
 	public static function cleanPictureLinks(string $text): string
 	{
 		DI::profiler()->startRecording('rendering');
-		$return = preg_replace_callback("&\[url=([^\[\]]*)\]\[img=(.*)\](.*)\[\/img\]\[\/url\]&Usi", 'self::cleanPictureLinksCallback', $text);
-		$return = preg_replace_callback("&\[url=([^\[\]]*)\]\[img\](.*)\[\/img\]\[\/url\]&Usi", 'self::cleanPictureLinksCallback', $return);
+		$return = preg_replace_callback("&\[url=([^\[\]]*)\]\[img=(.*)\](.*)\[\/img\]\[\/url\]&Usi", [self::class, 'cleanPictureLinksCallback'], $text);
+		$return = preg_replace_callback("&\[url=([^\[\]]*)\]\[img\](.*)\[\/img\]\[\/url\]&Usi", [self::class, 'cleanPictureLinksCallback'], $return);
 		DI::profiler()->stopRecording();
 		return $return;
 	}
@@ -1450,7 +1450,7 @@ class BBCode
 	{
 		DI::profiler()->startRecording('rendering');
 		$regexp = "/([@!])\[url\=([^\[\]]*)\].*?\[\/url\]/ism";
-		$body = preg_replace_callback($regexp, ['self', 'mentionCallback'], $body);
+		$body = preg_replace_callback($regexp, [self::class, 'mentionCallback'], $body);
 		DI::profiler()->stopRecording();
 		return $body;
 	}
@@ -2002,12 +2002,12 @@ class BBCode
 
 				if (!$for_plaintext) {
 					if (in_array($simple_html, [self::OSTATUS, self::MASTODON_API, self::TWITTER_API, self::ACTIVITYPUB])) {
-						$text = preg_replace_callback("/\[url\](.*?)\[\/url\]/ism", 'self::convertUrlForActivityPubCallback', $text);
-						$text = preg_replace_callback("/\[url\=(.*?)\](.*?)\[\/url\]/ism", 'self::convertUrlForActivityPubCallback', $text);
+						$text = preg_replace_callback("/\[url\](.*?)\[\/url\]/ism", [self::class, 'convertUrlForActivityPubCallback'], $text);
+						$text = preg_replace_callback("/\[url\=(.*?)\](.*?)\[\/url\]/ism", [self::class, 'convertUrlForActivityPubCallback'], $text);
 					}
 				} else {
 					$text = preg_replace("(\[url\](.*?)\[\/url\])ism", " $1 ", $text);
-					$text = preg_replace_callback("&\[url=([^\[\]]*)\]\[img\](.*)\[\/img\]\[\/url\]&Usi", 'self::removePictureLinksCallback', $text);
+					$text = preg_replace_callback("&\[url=([^\[\]]*)\]\[img\](.*)\[\/img\]\[\/url\]&Usi", [self::class, 'removePictureLinksCallback'], $text);
 				}
 
 				// Bookmarks in red - will be converted to bookmarks in friendica
@@ -2017,7 +2017,7 @@ class BBCode
 							"[bookmark=$1]$2[/bookmark]", $text);
 
 				if (in_array($simple_html, [self::OSTATUS, self::TWITTER])) {
-					$text = preg_replace_callback("/([^#@!])\[url\=([^\]]*)\](.*?)\[\/url\]/ism", "self::expandLinksCallback", $text);
+					$text = preg_replace_callback("/([^#@!])\[url\=([^\]]*)\](.*?)\[\/url\]/ism", [self::class, 'expandLinksCallback'], $text);
 					//$text = preg_replace("/[^#@!]\[url\=([^\]]*)\](.*?)\[\/url\]/ism", ' $2 [url]$1[/url]', $text);
 					$text = preg_replace("/\[bookmark\=([^\]]*)\](.*?)\[\/bookmark\]/ism", ' $2 [url]$1[/url]', $text);
 				}
@@ -2327,7 +2327,7 @@ class BBCode
 			$url_search_string = "^\[\]";
 			$text = preg_replace_callback(
 				"/([@!])\[(.*?)\]\(([$url_search_string]*?)\)/ism",
-				['self', 'bbCodeMention2DiasporaCallback'],
+				[self::class, 'bbCodeMention2DiasporaCallback'],
 				$text
 			);
 		}
diff --git a/src/Content/Text/HTML.php b/src/Content/Text/HTML.php
index c65e1d9820..f9f340135c 100644
--- a/src/Content/Text/HTML.php
+++ b/src/Content/Text/HTML.php
@@ -1032,7 +1032,7 @@ class HTML
 		// the quotes, e.g.:
 		//
 		//    concat("'foo'", '"', "bar")
-		return 'concat(' . implode(', \'"\', ', array_map(['self', 'xpathQuote'], explode('"', $value))) . ')';
+		return 'concat(' . implode(', \'"\', ', array_map([self::class, 'xpathQuote'], explode('"', $value))) . ')';
 	}
 
 	/**
diff --git a/src/Content/Widget/TagCloud.php b/src/Content/Widget/TagCloud.php
index 6f146f4ac1..53d332f0a8 100644
--- a/src/Content/Widget/TagCloud.php
+++ b/src/Content/Widget/TagCloud.php
@@ -144,7 +144,7 @@ class TagCloud
 			$x ++;
 		}
 
-		usort($tags, 'self::tagsSort');
+		usort($tags, [self::class, 'tagsSort']);
 		$range = max(0.01, $max - $min) * 1.0001;
 
 		for ($x = 0; $x < count($tags); $x ++) {
diff --git a/src/Database/DBA.php b/src/Database/DBA.php
index ffeecfaa71..e29cd30386 100644
--- a/src/Database/DBA.php
+++ b/src/Database/DBA.php
@@ -527,7 +527,7 @@ class DBA
 	public static function buildTableString(array $tables): string
 	{
 		// Quote each entry
-		return implode(',', array_map(['self', 'quoteIdentifier'], $tables));
+		return implode(',', array_map([self::class, 'quoteIdentifier'], $tables));
 	}
 
 	/**
@@ -717,7 +717,7 @@ class DBA
 	{
 		$groupby_string = '';
 		if (!empty($params['group_by'])) {
-			$groupby_string = " GROUP BY " . implode(', ', array_map(['self', 'quoteIdentifier'], $params['group_by']));
+			$groupby_string = " GROUP BY " . implode(', ', array_map([self::class, 'quoteIdentifier'], $params['group_by']));
 		}
 
 		$order_string = '';
diff --git a/src/Model/Event.php b/src/Model/Event.php
index ca22c32ac6..e39ee5fd56 100644
--- a/src/Model/Event.php
+++ b/src/Model/Event.php
@@ -198,7 +198,7 @@ class Event
 
 	public static function sortByDate(array $event_list): array
 	{
-		usort($event_list, ['self', 'compareDatesCallback']);
+		usort($event_list, [self::class, 'compareDatesCallback']);
 		return $event_list;
 	}
 
diff --git a/src/Navigation/Notifications/Repository/Notify.php b/src/Navigation/Notifications/Repository/Notify.php
index 87671f7e6a..2d15dd85c1 100644
--- a/src/Navigation/Notifications/Repository/Notify.php
+++ b/src/Navigation/Notifications/Repository/Notify.php
@@ -614,7 +614,7 @@ class Notify extends BaseRepository
 
 					$emailBuilder->setHeader('Message-ID', $message_id);
 					$log_msg = "No previous notification found for this parent:\n" .
-						"  parent: ${params['parent']}\n" . "  uid   : ${params['uid']}\n";
+						"  parent: {$params['parent']}\n" . "  uid   : {$params['uid']}\n";
 					$this->logger->info($log_msg);
 				} else {
 					// If not, just "follow" the thread.
diff --git a/src/Network/HTTPClient/Client/HttpClient.php b/src/Network/HTTPClient/Client/HttpClient.php
index 2ef704df1f..4ee0842150 100644
--- a/src/Network/HTTPClient/Client/HttpClient.php
+++ b/src/Network/HTTPClient/Client/HttpClient.php
@@ -69,6 +69,10 @@ class HttpClient implements ICanSendHttpRequests
 		$this->logger->debug('Request start.', ['url' => $url, 'method' => $method]);
 
 		$host = parse_url($url, PHP_URL_HOST);
+		if (empty($host)) {
+			throw new \InvalidArgumentException('Unable to retrieve the host in URL: ' . $url);
+		}
+
 		if(!filter_var($host, FILTER_VALIDATE_IP) && !@dns_get_record($host . '.', DNS_A + DNS_AAAA) && !gethostbyname($host)) {
 			$this->logger->debug('URL cannot be resolved.', ['url' => $url, 'callstack' => System::callstack(20)]);
 			$this->profiler->stopRecording();
diff --git a/src/Object/Api/Mastodon/Card.php b/src/Object/Api/Mastodon/Card.php
index d9b7344561..c4d21f66a3 100644
--- a/src/Object/Api/Mastodon/Card.php
+++ b/src/Object/Api/Mastodon/Card.php
@@ -54,6 +54,8 @@ class Card extends BaseDataTransferObject
 	protected $image;
 	/** @var string */
 	protected $blurhash;
+	/** @var array */
+	protected $history;
 
 	/**
 	 * Creates a card record from an attachment array.
diff --git a/src/Protocol/ActivityPub/Transmitter.php b/src/Protocol/ActivityPub/Transmitter.php
index 6e1180bca8..bcff0b53b1 100644
--- a/src/Protocol/ActivityPub/Transmitter.php
+++ b/src/Protocol/ActivityPub/Transmitter.php
@@ -1661,7 +1661,7 @@ class Transmitter
 		 *
 		 * } elseif (($type == 'Article') && empty($data['summary'])) {
 		 * 		$regexp = "/[@!]\[url\=([^\[\]]*)\].*?\[\/url\]/ism";
-		 * 		$summary = preg_replace_callback($regexp, ['self', 'mentionAddrCallback'], $body);
+		 * 		$summary = preg_replace_callback($regexp, [self::class, 'mentionAddrCallback'], $body);
 		 * 		$data['summary'] = BBCode::toPlaintext(Plaintext::shorten(self::removePictures($summary), 1000));
 		 * }
 		 */
diff --git a/src/Util/ParseUrl.php b/src/Util/ParseUrl.php
index 9d19a4ebac..f1e96dedc3 100644
--- a/src/Util/ParseUrl.php
+++ b/src/Util/ParseUrl.php
@@ -646,7 +646,7 @@ class ParseUrl
 		$arr_tags = str_getcsv($string);
 		if (count($arr_tags)) {
 			// add the # sign to every tag
-			array_walk($arr_tags, ['self', 'arrAddHashes']);
+			array_walk($arr_tags, [self::class, 'arrAddHashes']);
 
 			return $arr_tags;
 		}
diff --git a/src/Util/Proxy.php b/src/Util/Proxy.php
index 67a0becb04..7f3c946722 100644
--- a/src/Util/Proxy.php
+++ b/src/Util/Proxy.php
@@ -141,7 +141,7 @@ class Proxy
 	{
 		$html = str_replace(Strings::normaliseLink(DI::baseUrl()) . '/', DI::baseUrl() . '/', $html);
 
-		return preg_replace_callback('/(<img [^>]*src *= *["\'])([^"\']+)(["\'][^>]*>)/siU', 'self::replaceUrl', $html);
+		return preg_replace_callback('/(<img [^>]*src *= *["\'])([^"\']+)(["\'][^>]*>)/siU', [self::class, 'replaceUrl'], $html);
 	}
 
 	/**