diff --git a/src/Content/Conversation/Entity/Timeline.php b/src/Content/Conversation/Entity/Timeline.php
index 914f3795c6..a27d9fb98f 100644
--- a/src/Content/Conversation/Entity/Timeline.php
+++ b/src/Content/Conversation/Entity/Timeline.php
@@ -35,7 +35,7 @@ namespace Friendica\Content\Conversation\Entity;
  * @property-read array  $languages      Channel languages
  * @property-read int    $circle         Circle or timeline this channel is based on
  * @property-read bool   $publish        Publish the channel
- * @property-read bool   $valid          Signalizes that the search condiions are valid
+ * @property-read bool   $valid          Indicates that the search conditions are valid
  */
 class Timeline extends \Friendica\BaseEntity
 {
diff --git a/src/Core/L10n.php b/src/Core/L10n.php
index d00cd0df5c..2b1e7b9e4b 100644
--- a/src/Core/L10n.php
+++ b/src/Core/L10n.php
@@ -65,6 +65,9 @@ class L10n
 		'zh-cn' => '简体中文',
 	];
 
+	/** @var string Undetermined language */
+	const UNDETERMINED_LANGUAGE = 'un';
+
 	/**
 	 * A string indicating the current language used for translation:
 	 * - Two-letter ISO 639-1 code.
@@ -438,7 +441,7 @@ class L10n
 
 		// In ISO 639-2 undetermined languages have got the code "und".
 		// There is no official code for ISO 639-1, but "un" is not assigned to any language.   
-		$languages = ['un' => $this->t('Undetermined')];
+		$languages = [self::UNDETERMINED_LANGUAGE => $this->t('Undetermined')];
 
 		foreach ($this->getDetectableLanguages() as $code) {
 			$code     = $this->toISO6391($code);
diff --git a/src/Model/Item.php b/src/Model/Item.php
index f3fab4d965..91e7e8613e 100644
--- a/src/Model/Item.php
+++ b/src/Model/Item.php
@@ -28,6 +28,7 @@ use Friendica\Content\Post\Entity\PostMedia;
 use Friendica\Content\Text\BBCode;
 use Friendica\Content\Text\HTML;
 use Friendica\Core\Hook;
+use Friendica\Core\L10n;
 use Friendica\Core\Logger;
 use Friendica\Core\Protocol;
 use Friendica\Core\Renderer;
@@ -2124,7 +2125,7 @@ class Item
 	 */
 	public static function getLanguageArray(string $body, int $count, int $uri_id = 0, int $author_id = 0, array $default = []): array
 	{
-		$default = $default ?: ['un' => 1];
+		$default = $default ?: [L10n::UNDETERMINED_LANGUAGE => 1];
 
 		$searchtext = BBCode::toSearchText($body, $uri_id);
 
@@ -2274,7 +2275,7 @@ class Item
 		foreach (json_decode($item['language'], true) as $language => $reliability) {
 			$code = DI::l10n()->toISO6391($language);
 
-			if ($code == 'un') {
+			if ($code == L10n::UNDETERMINED_LANGUAGE) {
 				$native = $language = DI::l10n()->t('Undetermined');
 			} else {
 				$native   = $iso639->nativeByCode1($code);
diff --git a/src/Model/User.php b/src/Model/User.php
index e1e42e872a..20cc6ca82a 100644
--- a/src/Model/User.php
+++ b/src/Model/User.php
@@ -645,7 +645,7 @@ class User
 		}
 
 		if (!DI::config()->get('system', 'relay_deny_undetected_language')) {
-			$languages['un'] = 'un';
+			$languages[L10n::UNDETERMINED_LANGUAGE] = L10n::UNDETERMINED_LANGUAGE;
 		}
 
 		ksort($languages);
diff --git a/src/Protocol/Relay.php b/src/Protocol/Relay.php
index ae0ad949d0..9b1911315a 100644
--- a/src/Protocol/Relay.php
+++ b/src/Protocol/Relay.php
@@ -23,7 +23,7 @@ namespace Friendica\Protocol;
 
 use Friendica\Content\Smilies;
 use Friendica\Content\Text\BBCode;
-use Friendica\Core\Cache\Enum\Duration;
+use Friendica\Core\L10n;
 use Friendica\Core\Logger;
 use Friendica\Core\Protocol;
 use Friendica\Database\DBA;
@@ -189,7 +189,7 @@ class Relay
 		}
 
 		if (empty($detected) && empty($languages)) {
-			$detected = ['un'];
+			$detected = [L10n::UNDETERMINED_LANGUAGE];
 		}
 
 		if (empty($body) || Smilies::isEmojiPost($body)) {
diff --git a/view/lang/C/messages.po b/view/lang/C/messages.po
index 6caf64b1fd..2815e0948f 100644
--- a/view/lang/C/messages.po
+++ b/view/lang/C/messages.po
@@ -8,7 +8,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: 2024.03-dev\n"
 "Report-Msgid-Bugs-To: \n"
-"POT-Creation-Date: 2024-01-07 19:57+0000\n"
+"POT-Creation-Date: 2024-01-15 19:41+0000\n"
 "PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n"
 "Last-Translator: FULL NAME <EMAIL@ADDRESS>\n"
 "Language-Team: LANGUAGE <LL@li.org>\n"
@@ -1770,7 +1770,7 @@ msgstr ""
 msgid "Create new group"
 msgstr ""
 
-#: src/Content/Item.php:332 src/Model/Item.php:3205
+#: src/Content/Item.php:332 src/Model/Item.php:3235
 msgid "event"
 msgstr ""
 
@@ -1778,7 +1778,7 @@ msgstr ""
 msgid "status"
 msgstr ""
 
-#: src/Content/Item.php:341 src/Model/Item.php:3207
+#: src/Content/Item.php:341 src/Model/Item.php:3237
 #: src/Module/Post/Tag/Add.php:123
 msgid "photo"
 msgstr ""
@@ -2180,39 +2180,39 @@ msgstr ""
 msgid "last"
 msgstr ""
 
-#: src/Content/Text/BBCode.php:751 src/Content/Text/BBCode.php:1696
-#: src/Content/Text/BBCode.php:1697
+#: src/Content/Text/BBCode.php:755 src/Content/Text/BBCode.php:1700
+#: src/Content/Text/BBCode.php:1701
 msgid "Image/photo"
 msgstr ""
 
-#: src/Content/Text/BBCode.php:969
+#: src/Content/Text/BBCode.php:973
 #, php-format
 msgid ""
 "<a href=\"%1$s\" target=\"_blank\" rel=\"noopener noreferrer\">%2$s</a> %3$s"
 msgstr ""
 
-#: src/Content/Text/BBCode.php:994 src/Model/Item.php:3938
-#: src/Model/Item.php:3944 src/Model/Item.php:3945
+#: src/Content/Text/BBCode.php:998 src/Model/Item.php:3968
+#: src/Model/Item.php:3974 src/Model/Item.php:3975
 msgid "Link to source"
 msgstr ""
 
-#: src/Content/Text/BBCode.php:1603 src/Content/Text/HTML.php:904
+#: src/Content/Text/BBCode.php:1607 src/Content/Text/HTML.php:904
 msgid "Click to open/close"
 msgstr ""
 
-#: src/Content/Text/BBCode.php:1636
+#: src/Content/Text/BBCode.php:1640
 msgid "$1 wrote:"
 msgstr ""
 
-#: src/Content/Text/BBCode.php:1701 src/Content/Text/BBCode.php:1702
+#: src/Content/Text/BBCode.php:1705 src/Content/Text/BBCode.php:1706
 msgid "Encrypted content"
 msgstr ""
 
-#: src/Content/Text/BBCode.php:1957
+#: src/Content/Text/BBCode.php:1961
 msgid "Invalid source protocol"
 msgstr ""
 
-#: src/Content/Text/BBCode.php:1976
+#: src/Content/Text/BBCode.php:1980
 msgid "Invalid link protocol"
 msgstr ""
 
@@ -2424,12 +2424,12 @@ msgstr[1] ""
 msgid "More Trending Tags"
 msgstr ""
 
-#: src/Content/Widget/VCard.php:106 src/Model/Contact.php:1209
+#: src/Content/Widget/VCard.php:102 src/Model/Contact.php:1209
 #: src/Model/Profile.php:461
 msgid "Post to group"
 msgstr ""
 
-#: src/Content/Widget/VCard.php:110 src/Model/Contact.php:1214
+#: src/Content/Widget/VCard.php:106 src/Model/Contact.php:1214
 #: src/Model/Profile.php:466 src/Module/Moderation/Item/Source.php:85
 msgid "Mention"
 msgstr ""
@@ -2457,13 +2457,13 @@ msgstr ""
 msgid "Network:"
 msgstr ""
 
-#: src/Content/Widget/VCard.php:129 src/Model/Contact.php:1242
+#: src/Content/Widget/VCard.php:125 src/Model/Contact.php:1242
 #: src/Model/Contact.php:1254 src/Model/Profile.php:479
 #: src/Module/Contact/Profile.php:463
 msgid "Unfollow"
 msgstr ""
 
-#: src/Content/Widget/VCard.php:135 src/Model/Contact.php:1211
+#: src/Content/Widget/VCard.php:131 src/Model/Contact.php:1211
 #: src/Model/Profile.php:463
 msgid "View group"
 msgstr ""
@@ -2855,167 +2855,167 @@ msgstr ""
 msgid "Could not connect to database."
 msgstr ""
 
-#: src/Core/L10n.php:441 src/Model/Item.php:2249
+#: src/Core/L10n.php:444 src/Model/Item.php:2279
 msgid "Undetermined"
 msgstr ""
 
-#: src/Core/L10n.php:448
+#: src/Core/L10n.php:451
 #, php-format
 msgid "%s (%s)"
 msgstr ""
 
-#: src/Core/L10n.php:496 src/Model/Event.php:430
+#: src/Core/L10n.php:499 src/Model/Event.php:430
 #: src/Module/Settings/Display.php:284
 msgid "Monday"
 msgstr ""
 
-#: src/Core/L10n.php:496 src/Model/Event.php:431
+#: src/Core/L10n.php:499 src/Model/Event.php:431
 #: src/Module/Settings/Display.php:285
 msgid "Tuesday"
 msgstr ""
 
-#: src/Core/L10n.php:496 src/Model/Event.php:432
+#: src/Core/L10n.php:499 src/Model/Event.php:432
 #: src/Module/Settings/Display.php:286
 msgid "Wednesday"
 msgstr ""
 
-#: src/Core/L10n.php:496 src/Model/Event.php:433
+#: src/Core/L10n.php:499 src/Model/Event.php:433
 #: src/Module/Settings/Display.php:287
 msgid "Thursday"
 msgstr ""
 
-#: src/Core/L10n.php:496 src/Model/Event.php:434
+#: src/Core/L10n.php:499 src/Model/Event.php:434
 #: src/Module/Settings/Display.php:288
 msgid "Friday"
 msgstr ""
 
-#: src/Core/L10n.php:496 src/Model/Event.php:435
+#: src/Core/L10n.php:499 src/Model/Event.php:435
 #: src/Module/Settings/Display.php:289
 msgid "Saturday"
 msgstr ""
 
-#: src/Core/L10n.php:496 src/Model/Event.php:429
+#: src/Core/L10n.php:499 src/Model/Event.php:429
 #: src/Module/Settings/Display.php:283
 msgid "Sunday"
 msgstr ""
 
-#: src/Core/L10n.php:500 src/Model/Event.php:450
+#: src/Core/L10n.php:503 src/Model/Event.php:450
 msgid "January"
 msgstr ""
 
-#: src/Core/L10n.php:500 src/Model/Event.php:451
+#: src/Core/L10n.php:503 src/Model/Event.php:451
 msgid "February"
 msgstr ""
 
-#: src/Core/L10n.php:500 src/Model/Event.php:452
+#: src/Core/L10n.php:503 src/Model/Event.php:452
 msgid "March"
 msgstr ""
 
-#: src/Core/L10n.php:500 src/Model/Event.php:453
+#: src/Core/L10n.php:503 src/Model/Event.php:453
 msgid "April"
 msgstr ""
 
-#: src/Core/L10n.php:500 src/Core/L10n.php:519 src/Model/Event.php:441
+#: src/Core/L10n.php:503 src/Core/L10n.php:522 src/Model/Event.php:441
 msgid "May"
 msgstr ""
 
-#: src/Core/L10n.php:500 src/Model/Event.php:454
+#: src/Core/L10n.php:503 src/Model/Event.php:454
 msgid "June"
 msgstr ""
 
-#: src/Core/L10n.php:500 src/Model/Event.php:455
+#: src/Core/L10n.php:503 src/Model/Event.php:455
 msgid "July"
 msgstr ""
 
-#: src/Core/L10n.php:500 src/Model/Event.php:456
+#: src/Core/L10n.php:503 src/Model/Event.php:456
 msgid "August"
 msgstr ""
 
-#: src/Core/L10n.php:500 src/Model/Event.php:457
+#: src/Core/L10n.php:503 src/Model/Event.php:457
 msgid "September"
 msgstr ""
 
-#: src/Core/L10n.php:500 src/Model/Event.php:458
+#: src/Core/L10n.php:503 src/Model/Event.php:458
 msgid "October"
 msgstr ""
 
-#: src/Core/L10n.php:500 src/Model/Event.php:459
+#: src/Core/L10n.php:503 src/Model/Event.php:459
 msgid "November"
 msgstr ""
 
-#: src/Core/L10n.php:500 src/Model/Event.php:460
+#: src/Core/L10n.php:503 src/Model/Event.php:460
 msgid "December"
 msgstr ""
 
-#: src/Core/L10n.php:515 src/Model/Event.php:422
+#: src/Core/L10n.php:518 src/Model/Event.php:422
 msgid "Mon"
 msgstr ""
 
-#: src/Core/L10n.php:515 src/Model/Event.php:423
+#: src/Core/L10n.php:518 src/Model/Event.php:423
 msgid "Tue"
 msgstr ""
 
-#: src/Core/L10n.php:515 src/Model/Event.php:424
+#: src/Core/L10n.php:518 src/Model/Event.php:424
 msgid "Wed"
 msgstr ""
 
-#: src/Core/L10n.php:515 src/Model/Event.php:425
+#: src/Core/L10n.php:518 src/Model/Event.php:425
 msgid "Thu"
 msgstr ""
 
-#: src/Core/L10n.php:515 src/Model/Event.php:426
+#: src/Core/L10n.php:518 src/Model/Event.php:426
 msgid "Fri"
 msgstr ""
 
-#: src/Core/L10n.php:515 src/Model/Event.php:427
+#: src/Core/L10n.php:518 src/Model/Event.php:427
 msgid "Sat"
 msgstr ""
 
-#: src/Core/L10n.php:515 src/Model/Event.php:421
+#: src/Core/L10n.php:518 src/Model/Event.php:421
 msgid "Sun"
 msgstr ""
 
-#: src/Core/L10n.php:519 src/Model/Event.php:437
+#: src/Core/L10n.php:522 src/Model/Event.php:437
 msgid "Jan"
 msgstr ""
 
-#: src/Core/L10n.php:519 src/Model/Event.php:438
+#: src/Core/L10n.php:522 src/Model/Event.php:438
 msgid "Feb"
 msgstr ""
 
-#: src/Core/L10n.php:519 src/Model/Event.php:439
+#: src/Core/L10n.php:522 src/Model/Event.php:439
 msgid "Mar"
 msgstr ""
 
-#: src/Core/L10n.php:519 src/Model/Event.php:440
+#: src/Core/L10n.php:522 src/Model/Event.php:440
 msgid "Apr"
 msgstr ""
 
-#: src/Core/L10n.php:519 src/Model/Event.php:442
+#: src/Core/L10n.php:522 src/Model/Event.php:442
 msgid "Jun"
 msgstr ""
 
-#: src/Core/L10n.php:519 src/Model/Event.php:443
+#: src/Core/L10n.php:522 src/Model/Event.php:443
 msgid "Jul"
 msgstr ""
 
-#: src/Core/L10n.php:519 src/Model/Event.php:444
+#: src/Core/L10n.php:522 src/Model/Event.php:444
 msgid "Aug"
 msgstr ""
 
-#: src/Core/L10n.php:519
+#: src/Core/L10n.php:522
 msgid "Sep"
 msgstr ""
 
-#: src/Core/L10n.php:519 src/Model/Event.php:446
+#: src/Core/L10n.php:522 src/Model/Event.php:446
 msgid "Oct"
 msgstr ""
 
-#: src/Core/L10n.php:519 src/Model/Event.php:447
+#: src/Core/L10n.php:522 src/Model/Event.php:447
 msgid "Nov"
 msgstr ""
 
-#: src/Core/L10n.php:519 src/Model/Event.php:448
+#: src/Core/L10n.php:522 src/Model/Event.php:448
 msgid "Dec"
 msgstr ""
 
@@ -3413,91 +3413,91 @@ msgstr ""
 msgid "Happy Birthday %s"
 msgstr ""
 
-#: src/Model/Item.php:2256
+#: src/Model/Item.php:2286
 #, php-format
 msgid "%s (%s - %s): %s"
 msgstr ""
 
-#: src/Model/Item.php:2258
+#: src/Model/Item.php:2288
 #, php-format
 msgid "%s (%s): %s"
 msgstr ""
 
-#: src/Model/Item.php:2261
+#: src/Model/Item.php:2291
 #, php-format
 msgid "Detected languages in this post:\\n%s"
 msgstr ""
 
-#: src/Model/Item.php:3209
+#: src/Model/Item.php:3239
 msgid "activity"
 msgstr ""
 
-#: src/Model/Item.php:3211
+#: src/Model/Item.php:3241
 msgid "comment"
 msgstr ""
 
-#: src/Model/Item.php:3214 src/Module/Post/Tag/Add.php:123
+#: src/Model/Item.php:3244 src/Module/Post/Tag/Add.php:123
 msgid "post"
 msgstr ""
 
-#: src/Model/Item.php:3384
+#: src/Model/Item.php:3414
 #, php-format
 msgid "%s is blocked"
 msgstr ""
 
-#: src/Model/Item.php:3386
+#: src/Model/Item.php:3416
 #, php-format
 msgid "%s is ignored"
 msgstr ""
 
-#: src/Model/Item.php:3388
+#: src/Model/Item.php:3418
 #, php-format
 msgid "Content from %s is collapsed"
 msgstr ""
 
-#: src/Model/Item.php:3392
+#: src/Model/Item.php:3422
 #, php-format
 msgid "Content warning: %s"
 msgstr ""
 
-#: src/Model/Item.php:3845
+#: src/Model/Item.php:3875
 msgid "bytes"
 msgstr ""
 
-#: src/Model/Item.php:3876
+#: src/Model/Item.php:3906
 #, php-format
 msgid "%2$s (%3$d%%, %1$d vote)"
 msgid_plural "%2$s (%3$d%%, %1$d votes)"
 msgstr[0] ""
 msgstr[1] ""
 
-#: src/Model/Item.php:3878
+#: src/Model/Item.php:3908
 #, php-format
 msgid "%2$s (%1$d vote)"
 msgid_plural "%2$s (%1$d votes)"
 msgstr[0] ""
 msgstr[1] ""
 
-#: src/Model/Item.php:3883
+#: src/Model/Item.php:3913
 #, php-format
 msgid "%d voter. Poll end: %s"
 msgid_plural "%d voters. Poll end: %s"
 msgstr[0] ""
 msgstr[1] ""
 
-#: src/Model/Item.php:3885
+#: src/Model/Item.php:3915
 #, php-format
 msgid "%d voter."
 msgid_plural "%d voters."
 msgstr[0] ""
 msgstr[1] ""
 
-#: src/Model/Item.php:3887
+#: src/Model/Item.php:3917
 #, php-format
 msgid "Poll end: %s"
 msgstr ""
 
-#: src/Model/Item.php:3921 src/Model/Item.php:3922
+#: src/Model/Item.php:3951 src/Model/Item.php:3952
 msgid "View on separate page"
 msgstr ""
 
@@ -3505,7 +3505,7 @@ msgstr ""
 msgid "[no subject]"
 msgstr ""
 
-#: src/Model/Photo.php:1190 src/Module/Media/Photo/Upload.php:170
+#: src/Model/Photo.php:1191 src/Module/Media/Photo/Upload.php:170
 msgid "Wall Photos"
 msgstr ""
 
@@ -3793,7 +3793,7 @@ msgstr ""
 msgid "Profile Photos"
 msgstr ""
 
-#: src/Model/User.php:1592
+#: src/Model/User.php:1594
 #, php-format
 msgid ""
 "\n"
@@ -3801,7 +3801,7 @@ msgid ""
 "\t\t\tthe administrator of %2$s has set up an account for you."
 msgstr ""
 
-#: src/Model/User.php:1595
+#: src/Model/User.php:1597
 #, php-format
 msgid ""
 "\n"
@@ -3837,12 +3837,12 @@ msgid ""
 "\t\tThank you and welcome to %4$s."
 msgstr ""
 
-#: src/Model/User.php:1627 src/Model/User.php:1733
+#: src/Model/User.php:1629 src/Model/User.php:1735
 #, php-format
 msgid "Registration details for %s"
 msgstr ""
 
-#: src/Model/User.php:1647
+#: src/Model/User.php:1649
 #, php-format
 msgid ""
 "\n"
@@ -3858,12 +3858,12 @@ msgid ""
 "\t\t"
 msgstr ""
 
-#: src/Model/User.php:1666
+#: src/Model/User.php:1668
 #, php-format
 msgid "Registration at %s"
 msgstr ""
 
-#: src/Model/User.php:1690
+#: src/Model/User.php:1692
 #, php-format
 msgid ""
 "\n"
@@ -3872,7 +3872,7 @@ msgid ""
 "\t\t\t"
 msgstr ""
 
-#: src/Model/User.php:1698
+#: src/Model/User.php:1700
 #, php-format
 msgid ""
 "\n"
@@ -3910,7 +3910,7 @@ msgid ""
 "\t\t\tThank you and welcome to %2$s."
 msgstr ""
 
-#: src/Model/User.php:1760
+#: src/Model/User.php:1762
 msgid ""
 "User with delegates can't be removed, please remove delegate users first"
 msgstr ""