diff --git a/boot.php b/boot.php
index 1716956fa1..60c8bf5a30 100644
--- a/boot.php
+++ b/boot.php
@@ -29,18 +29,6 @@
 
 use Friendica\Core\Session;
 
-/**
- * @name Gravity
- *
- * Item weight for query ordering
- * @{
- */
-define('GRAVITY_PARENT',       0);
-define('GRAVITY_ACTIVITY',     3);
-define('GRAVITY_COMMENT',      6);
-define('GRAVITY_UNKNOWN',      9);
-/* @}*/
-
 /**
  * Returns the user id of locally logged in user or false.
  *
diff --git a/mod/display.php b/mod/display.php
index 5aba7eb81d..c1b7746e24 100644
--- a/mod/display.php
+++ b/mod/display.php
@@ -106,7 +106,7 @@ function display_init(App $a)
 		displayShowFeed($item['uri-id'], $item['uid'], false);
 	}
 
-	if ($item['gravity'] != GRAVITY_PARENT) {
+	if ($item['gravity'] != Item::GRAVITY_PARENT) {
 		$parent = Post::selectFirstForUser($item_user, $fields, ['uid' => [0, $item_user], 'uri-id' => $item['parent-uri-id']], ['order' => ['uid' => true]]);
 		$item = $parent ?: $item;
 	}
diff --git a/mod/events.php b/mod/events.php
index f1d8a7ca60..a9a2e47fe2 100644
--- a/mod/events.php
+++ b/mod/events.php
@@ -173,22 +173,23 @@ function events_post(App $a)
 		$private_event = true;
 	}
 
-	$datarray = [];
-	$datarray['start']     = $start;
-	$datarray['finish']    = $finish;
-	$datarray['summary']   = $summary;
-	$datarray['desc']      = $desc;
-	$datarray['location']  = $location;
-	$datarray['type']      = $type;
-	$datarray['nofinish']  = $nofinish;
-	$datarray['uid']       = $uid;
-	$datarray['cid']       = $cid;
-	$datarray['allow_cid'] = $str_contact_allow;
-	$datarray['allow_gid'] = $str_group_allow;
-	$datarray['deny_cid']  = $str_contact_deny;
-	$datarray['deny_gid']  = $str_group_deny;
-	$datarray['private']   = $private_event;
-	$datarray['id']        = $event_id;
+	$datarray = [
+		'start'     => $start,
+		'finish'    => $finish,
+		'summary'   => $summary,
+		'desc'      => $desc,
+		'location'  => $location,
+		'type'      => $type,
+		'nofinish'  => $nofinish,
+		'uid'       => $uid,
+		'cid'       => $cid,
+		'allow_cid' => $str_contact_allow,
+		'allow_gid' => $str_group_allow,
+		'deny_cid'  => $str_contact_deny,
+		'deny_gid'  => $str_group_deny,
+		'private'   => $private_event,
+		'id'        => $event_id,
+	];
 
 	if (intval($_REQUEST['preview'])) {
 		System::httpExit(Event::getHTML($datarray));
diff --git a/mod/item.php b/mod/item.php
index cc8e953858..799d1b8881 100644
--- a/mod/item.php
+++ b/mod/item.php
@@ -123,7 +123,7 @@ function item_post(App $a) {
 			$thr_parent_uri = $parent_item['uri'];
 			$toplevel_item = $parent_item;
 
-			if ($parent_item['gravity'] != GRAVITY_PARENT) {
+			if ($parent_item['gravity'] != Item::GRAVITY_PARENT) {
 				$toplevel_item = Post::selectFirst(Item::ITEM_FIELDLIST, ['id' => $toplevel_item['parent']]);
 			}
 		}
@@ -308,7 +308,7 @@ function item_post(App $a) {
 			// for non native networks use the network of the original post as network of the item
 			if (($toplevel_item['network'] != Protocol::DIASPORA)
 				&& ($toplevel_item['network'] != Protocol::OSTATUS)
-				&& ($network == "")) {
+				&& ($network == '')) {
 				$network = $toplevel_item['network'];
 			}
 
@@ -386,7 +386,7 @@ function item_post(App $a) {
 		// Look for any tags and linkify them
 		$item = [
 			'uid'       => local_user() ? local_user() : $profile_uid,
-			'gravity'   => $toplevel_item_id ? GRAVITY_COMMENT : GRAVITY_PARENT,
+			'gravity'   => $toplevel_item_id ? Item::GRAVITY_COMMENT : Item::GRAVITY_PARENT,
 			'network'   => $network,
 			'body'      => $body,
 			'postopts'  => $postopts,
@@ -463,7 +463,7 @@ function item_post(App $a) {
 
 	$data = BBCode::getAttachmentData($body);
 	$match = [];
-	if ((preg_match_all("/\[bookmark\=([^\]]*)\](.*?)\[\/bookmark\]/ism", $body, $match, PREG_SET_ORDER) || isset($data["type"]))
+	if ((preg_match_all("/\[bookmark\=([^\]]*)\](.*?)\[\/bookmark\]/ism", $body, $match, PREG_SET_ORDER) || isset($data['type']))
 		&& ($posttype != Item::PT_PERSONAL_NOTE)) {
 		$posttype = Item::PT_PAGE;
 		$objecttype =  Activity\ObjectType::BOOKMARK;
@@ -478,11 +478,11 @@ function item_post(App $a) {
 		$objecttype = Activity\ObjectType::NOTE; // Default value
 		$objectdata = BBCode::getAttachedData($body);
 
-		if ($objectdata["type"] == "link") {
+		if ($objectdata['type'] == 'link') {
 			$objecttype = Activity\ObjectType::BOOKMARK;
-		} elseif ($objectdata["type"] == "video") {
+		} elseif ($objectdata['type'] == 'video') {
 			$objecttype = Activity\ObjectType::VIDEO;
-		} elseif ($objectdata["type"] == "photo") {
+		} elseif ($objectdata['type'] == 'photo') {
 			$objecttype = Activity\ObjectType::IMAGE;
 		}
 
@@ -510,11 +510,11 @@ function item_post(App $a) {
 		$verb = Activity::POST;
 	}
 
-	if ($network == "") {
+	if ($network == '') {
 		$network = Protocol::DFRN;
 	}
 
-	$gravity = ($toplevel_item_id ? GRAVITY_COMMENT : GRAVITY_PARENT);
+	$gravity = ($toplevel_item_id ? Item::GRAVITY_COMMENT : Item::GRAVITY_PARENT);
 
 	// even if the post arrived via API we are considering that it
 	// originated on this site by default for determining relayability.
@@ -533,68 +533,65 @@ function item_post(App $a) {
 		$thr_parent_uri = $uri;
 	}
 
-	$datarray = [];
-	$datarray['uid']           = $profile_uid;
-	$datarray['wall']          = $wall;
-	$datarray['gravity']       = $gravity;
-	$datarray['network']       = $network;
-	$datarray['contact-id']    = $contact_id;
-	$datarray['owner-name']    = $contact_record['name'] ?? '';
-	$datarray['owner-link']    = $contact_record['url'] ?? '';
-	$datarray['owner-avatar']  = $contact_record['thumb'] ?? '';
-	$datarray['owner-id']      = Contact::getIdForURL($datarray['owner-link']);
-	$datarray['author-name']   = $author['name'];
-	$datarray['author-link']   = $author['url'];
-	$datarray['author-avatar'] = $author['thumb'];
-	$datarray['author-id']     = Contact::getIdForURL($datarray['author-link']);
-	$datarray['created']       = empty($_REQUEST['created_at']) ? DateTimeFormat::utcNow() : $_REQUEST['created_at'];
-	$datarray['edited']        = $datarray['created'];
-	$datarray['commented']     = $datarray['created'];
-	$datarray['changed']       = $datarray['created'];
-	$datarray['received']      = DateTimeFormat::utcNow();
-	$datarray['extid']         = $extid;
-	$datarray['guid']          = $guid;
-	$datarray['uri']           = $uri;
-	$datarray['title']         = $title;
-	$datarray['body']          = $body;
-	$datarray['app']           = $app;
-	$datarray['location']      = $location;
-	$datarray['coord']         = $coord;
-	$datarray['file']          = $categories;
-	$datarray['inform']        = $inform;
-	$datarray['verb']          = $verb;
-	$datarray['post-type']     = $posttype;
-	$datarray['object-type']   = $objecttype;
-	$datarray['allow_cid']     = $str_contact_allow;
-	$datarray['allow_gid']     = $str_group_allow;
-	$datarray['deny_cid']      = $str_contact_deny;
-	$datarray['deny_gid']      = $str_group_deny;
-	$datarray['private']       = $private;
-	$datarray['pubmail']       = $pubmail_enabled;
-	$datarray['attach']        = $attachments;
+	$datarray = [
+		'uid'           => $profile_uid,
+		'wall'          => $wall,
+		'gravity'       => $gravity,
+		'network'       => $network,
+		'contact-id'    => $contact_id,
+		'owner-name'    => $contact_record['name'] ?? '',
+		'owner-link'    => $contact_record['url'] ?? '',
+		'owner-avatar'  => $contact_record['thumb'] ?? '',
+		'author-name'   => $author['name'],
+		'author-link'   => $author['url'],
+		'author-avatar' => $author['thumb'],
+		'created'       => empty($_REQUEST['created_at']) ? DateTimeFormat::utcNow() : $_REQUEST['created_at'],
+		'received'      => DateTimeFormat::utcNow(),
+		'extid'         => $extid,
+		'guid'          => $guid,
+		'uri'           => $uri,
+		'title'         => $title,
+		'body'          => $body,
+		'app'           => $app,
+		'location'      => $location,
+		'coord'         => $coord,
+		'file'          => $categories,
+		'inform'        => $inform,
+		'verb'          => $verb,
+		'post-type'     => $posttype,
+		'object-type'   => $objecttype,
+		'allow_cid'     => $str_contact_allow,
+		'allow_gid'     => $str_group_allow,
+		'deny_cid'      => $str_contact_deny,
+		'deny_gid'      => $str_group_deny,
+		'private'       => $private,
+		'pubmail'       => $pubmail_enabled,
+		'attach'        => $attachments,
+		'thr-parent'    => $thr_parent_uri,
+		'postopts'      => $postopts,
+		'origin'        => $origin,
+		'object'        => $object,
+		'attachments'   => $_REQUEST['attachments'] ?? [],
+		/*
+		 * These fields are for the convenience of addons...
+		 * 'self' if true indicates the owner is posting on their own wall
+		 * If parent is 0 it is a top-level post.
+		 */
+		'parent'        => $toplevel_item_id,
+		'self'          => $self,
+		// This triggers posts via API and the mirror functions
+		'api_source'    => $api_source,
+		// This field is for storing the raw conversation data
+		'protocol'      => Conversation::PARCEL_DIRECT,
+		'direction'     => Conversation::PUSH,
+	];
 
-	$datarray['thr-parent']    = $thr_parent_uri;
-
-	$datarray['postopts']      = $postopts;
-	$datarray['origin']        = $origin;
-	$datarray['object']        = $object;
-
-	$datarray['attachments']   = $_REQUEST['attachments'] ?? [];
-
-	/*
-	 * These fields are for the convenience of addons...
-	 * 'self' if true indicates the owner is posting on their own wall
-	 * If parent is 0 it is a top-level post.
-	 */
-	$datarray['parent']        = $toplevel_item_id;
-	$datarray['self']          = $self;
-
-	// This triggers posts via API and the mirror functions
-	$datarray['api_source'] = $api_source;
-
-	// This field is for storing the raw conversation data
-	$datarray['protocol'] = Conversation::PARCEL_DIRECT;
-	$datarray['direction'] = Conversation::PUSH;
+	// These cannot be part of above initialization ...
+	$datarray['edited']    = $datarray['created'];
+	$datarray['commented'] = $datarray['created'];
+	$datarray['changed']   = $datarray['created'];
+	$datarray['owner-id']  = Contact::getIdForURL($datarray['owner-link']);
+	$datarray['author-id'] = Contact::getIdForURL($datarray['author-link']);
 
 	$datarray['edit'] = $orig_post;
 
@@ -607,14 +604,14 @@ function item_post(App $a) {
 	if ($preview) {
 		// We set the datarray ID to -1 because in preview mode the dataray
 		// doesn't have an ID.
-		$datarray["id"] = -1;
-		$datarray["uri-id"] = -1;
-		$datarray["author-network"] = Protocol::DFRN;
-		$datarray["author-updated"] = '';
-		$datarray["author-gsid"] = 0;
-		$datarray["author-uri-id"] = ItemURI::getIdByURI($datarray["author-link"]);
-		$datarray["owner-updated"] = '';
-		$datarray["has-media"] = false;
+		$datarray['id'] = -1;
+		$datarray['uri-id'] = -1;
+		$datarray['author-network'] = Protocol::DFRN;
+		$datarray['author-updated'] = '';
+		$datarray['author-gsid'] = 0;
+		$datarray['author-uri-id'] = ItemURI::getIdByURI($datarray['author-link']);
+		$datarray['owner-updated'] = '';
+		$datarray['has-media'] = false;
 		$datarray['body'] = Item::improveSharedDataInBody($datarray);
 
 		$o = DI::conversation()->create([array_merge($contact_record, $datarray)], 'search', false, true);
@@ -658,13 +655,13 @@ function item_post(App $a) {
 	$datarray['uri-id'] = ItemURI::getIdByURI($datarray['uri']);
 	$datarray['body']   = Item::improveSharedDataInBody($datarray);
 
-	if ($orig_post)	{
+	if ($orig_post) {
 		$fields = [
-			'title' => $datarray['title'],
-			'body' => $datarray['body'],
-			'attach' => $datarray['attach'],
-			'file' => $datarray['file'],
-			'edited' => DateTimeFormat::utcNow(),
+			'title'   => $datarray['title'],
+			'body'    => $datarray['body'],
+			'attach'  => $datarray['attach'],
+			'file'    => $datarray['file'],
+			'edited'  => DateTimeFormat::utcNow(),
 			'changed' => DateTimeFormat::utcNow()
 		];
 
@@ -706,7 +703,7 @@ function item_post(App $a) {
 
 	Tag::storeFromBody($datarray['uri-id'], $datarray['body']);
 
-	if (!\Friendica\Content\Feature::isEnabled($uid, 'explicit_mentions') && ($datarray['gravity'] == GRAVITY_COMMENT)) {
+	if (!\Friendica\Content\Feature::isEnabled($uid, 'explicit_mentions') && ($datarray['gravity'] == Item::GRAVITY_COMMENT)) {
 		Tag::createImplicitMentions($datarray['uri-id'], $datarray['thr-parent-id']);
 	}
 
@@ -808,6 +805,7 @@ function item_content(App $a)
 				}
 			}
 			break;
+
 		case 'block':
 			$item = Post::selectFirstForUser(local_user(), ['guid', 'author-id', 'parent', 'gravity'], ['id' => $args->get(2)]);
 			if (empty($item['author-id'])) {
@@ -834,15 +832,15 @@ function item_content(App $a)
  * @return string
  * @throws HTTPException\InternalServerErrorException
  */
-function drop_item(int $id, string $return = '')
+function drop_item(int $id, string $return = ''): string
 {
-	// locate item to be deleted
-	$fields = ['id', 'uid', 'guid', 'contact-id', 'deleted', 'gravity', 'parent'];
-	$item = Post::selectFirstForUser(local_user(), $fields, ['id' => $id]);
+	// Locate item to be deleted
+	$item = Post::selectFirstForUser(local_user(), ['id', 'uid', 'guid', 'contact-id', 'deleted', 'gravity', 'parent'], ['id' => $id]);
 
 	if (!DBA::isResult($item)) {
 		DI::sysmsg()->addNotice(DI::l10n()->t('Item not found.'));
 		DI::baseUrl()->redirect('network');
+		//NOTREACHED
 	}
 
 	if ($item['deleted']) {
@@ -861,6 +859,7 @@ function drop_item(int $id, string $return = '')
 		Item::deleteForUser(['id' => $item['id']], local_user());
 
 		item_redirect_after_action($item, $return);
+		//NOTREACHED
 	} else {
 		Logger::warning('Permission denied.', ['local' => local_user(), 'uid' => $item['uid'], 'cid' => $contact_id]);
 		DI::sysmsg()->addNotice(DI::l10n()->t('Permission denied.'));
@@ -871,15 +870,15 @@ function drop_item(int $id, string $return = '')
 	return '';
 }
 
-function item_redirect_after_action($item, $returnUrlHex)
+function item_redirect_after_action(array $item, string $returnUrlHex)
 {
 	$return_url = hex2bin($returnUrlHex);
 
 	// removes update_* from return_url to ignore Ajax refresh
-	$return_url = str_replace("update_", "", $return_url);
+	$return_url = str_replace('update_', '', $return_url);
 
 	// Check if delete a comment
-	if ($item['gravity'] == GRAVITY_COMMENT) {
+	if ($item['gravity'] == Item::GRAVITY_COMMENT) {
 		if (!empty($item['parent'])) {
 			$parentitem = Post::selectFirstForUser(local_user(), ['guid'], ['id' => $item['parent']]);
 		}
diff --git a/mod/message.php b/mod/message.php
index d1231b7c5d..4b6f5b31b8 100644
--- a/mod/message.php
+++ b/mod/message.php
@@ -43,23 +43,23 @@ function message_init(App $a)
 	}
 
 	$new = [
-		'label' => DI::l10n()->t('New Message'),
-		'url' => 'message/new',
-		'sel' => DI::args()->getArgc() > 1 && DI::args()->getArgv()[1] == 'new',
+		'label'     => DI::l10n()->t('New Message'),
+		'url'       => 'message/new',
+		'sel'       => DI::args()->getArgc() > 1 && DI::args()->getArgv()[1] == 'new',
 		'accesskey' => 'm',
 	];
 
 	$tpl = Renderer::getMarkupTemplate('message_side.tpl');
 	DI::page()['aside'] = Renderer::replaceMacros($tpl, [
 		'$tabs' => $tabs,
-		'$new' => $new,
+		'$new'  => $new,
 	]);
 	$base = DI::baseUrl();
 
 	$head_tpl = Renderer::getMarkupTemplate('message-head.tpl');
 	DI::page()['htmlhead'] .= Renderer::replaceMacros($head_tpl, [
 		'$baseurl' => DI::baseUrl()->get(true),
-		'$base' => $base
+		'$base'    => $base
 	]);
 }
 
@@ -83,12 +83,15 @@ function message_post(App $a)
 			DI::sysmsg()->addNotice(DI::l10n()->t('No recipient selected.'));
 			$norecip = true;
 			break;
+
 		case -2:
 			DI::sysmsg()->addNotice(DI::l10n()->t('Unable to locate contact information.'));
 			break;
+
 		case -3:
 			DI::sysmsg()->addNotice(DI::l10n()->t('Message could not be sent.'));
 			break;
+
 		case -4:
 			DI::sysmsg()->addNotice(DI::l10n()->t('Message collection failure.'));
 			break;
@@ -118,20 +121,20 @@ function message_content(App $a)
 	if (DI::args()->getArgc() > 1 && DI::args()->getArgv()[1] == 'new') {
 		$button = [
 			'label' => DI::l10n()->t('Discard'),
-			'url' => '/message',
-			'sel' => 'close',
+			'url'   => '/message',
+			'sel'   => 'close',
 		];
 	} else {
 		$button = [
-			'label' => DI::l10n()->t('New Message'),
-			'url' => '/message/new',
-			'sel' => 'new',
+			'label'     => DI::l10n()->t('New Message'),
+			'url'       => '/message/new',
+			'sel'       => 'new',
 			'accesskey' => 'm',
 		];
 	}
 	$header = Renderer::replaceMacros($tpl, [
 		'$messages' => DI::l10n()->t('Messages'),
-		'$button' => $button,
+		'$button'   => $button,
 	]);
 
 	if ((DI::args()->getArgc() == 3) && (DI::args()->getArgv()[1] === 'drop' || DI::args()->getArgv()[1] === 'dropconv')) {
@@ -186,19 +189,19 @@ function message_content(App $a)
 
 		$tpl = Renderer::getMarkupTemplate('prv_message.tpl');
 		$o .= Renderer::replaceMacros($tpl, [
-			'$header'     => DI::l10n()->t('Send Private Message'),
-			'$to'         => DI::l10n()->t('To:'),
-			'$subject'    => DI::l10n()->t('Subject:'),
-			'$subjtxt'    => $_REQUEST['subject'] ?? '',
-			'$text'       => $_REQUEST['body'] ?? '',
-			'$readonly'   => '',
-			'$yourmessage'=> DI::l10n()->t('Your message:'),
-			'$select'     => $select,
-			'$parent'     => '',
-			'$upload'     => DI::l10n()->t('Upload photo'),
-			'$insert'     => DI::l10n()->t('Insert web link'),
-			'$wait'       => DI::l10n()->t('Please wait'),
-			'$submit'     => DI::l10n()->t('Submit')
+			'$header'      => DI::l10n()->t('Send Private Message'),
+			'$to'          => DI::l10n()->t('To:'),
+			'$subject'     => DI::l10n()->t('Subject:'),
+			'$subjtxt'     => $_REQUEST['subject'] ?? '',
+			'$text'        => $_REQUEST['body'] ?? '',
+			'$readonly'    => '',
+			'$yourmessage' => DI::l10n()->t('Your message:'),
+			'$select'      => $select,
+			'$parent'      => '',
+			'$upload'      => DI::l10n()->t('Upload photo'),
+			'$insert'      => DI::l10n()->t('Insert web link'),
+			'$wait'        => DI::l10n()->t('Please wait'),
+			'$submit'      => DI::l10n()->t('Submit')
 		]);
 		return $o;
 	}
@@ -312,18 +315,18 @@ function message_content(App $a)
 			$from_photo = Contact::getThumb($contact);
 
 			$mails[] = [
-				'id' => $message['id'],
-				'from_name' => $from_name_e,
-				'from_url' => $from_url,
-				'from_addr' => $contact['addr'] ?? $from_url,
-				'sparkle' => $sparkle,
+				'id'         => $message['id'],
+				'from_name'  => $from_name_e,
+				'from_url'   => $from_url,
+				'from_addr'  => $contact['addr'] ?? $from_url,
+				'sparkle'    => $sparkle,
 				'from_photo' => $from_photo,
-				'subject' => $subject_e,
-				'body' => $body_e,
-				'delete' => DI::l10n()->t('Delete message'),
-				'to_name' => $to_name_e,
-				'date' => DateTimeFormat::local($message['created'], DI::l10n()->t('D, d M Y - g:i A')),
-				'ago' => Temporal::getRelativeDate($message['created']),
+				'subject'    => $subject_e,
+				'body'       => $body_e,
+				'delete'     => DI::l10n()->t('Delete message'),
+				'to_name'    => $to_name_e,
+				'date'       => DateTimeFormat::local($message['created'], DI::l10n()->t('D, d M Y - g:i A')),
+				'ago'        => Temporal::getRelativeDate($message['created']),
 			];
 
 			$seen = $message['seen'];
@@ -334,28 +337,27 @@ function message_content(App $a)
 
 		$tpl = Renderer::getMarkupTemplate('mail_display.tpl');
 		$o = Renderer::replaceMacros($tpl, [
-			'$thread_id' => DI::args()->getArgv()[1],
+			'$thread_id'      => DI::args()->getArgv()[1],
 			'$thread_subject' => $message['title'],
-			'$thread_seen' => $seen,
-			'$delete' => DI::l10n()->t('Delete conversation'),
-			'$canreply' => (($unknown) ? false : '1'),
-			'$unknown_text' => DI::l10n()->t("No secure communications available. You <strong>may</strong> be able to respond from the sender's profile page."),
-			'$mails' => $mails,
-
+			'$thread_seen'    => $seen,
+			'$delete'         => DI::l10n()->t('Delete conversation'),
+			'$canreply'       => (($unknown) ? false : '1'),
+			'$unknown_text'   => DI::l10n()->t("No secure communications available. You <strong>may</strong> be able to respond from the sender's profile page."),
+			'$mails'          => $mails,
 			// reply
-			'$header' => DI::l10n()->t('Send Reply'),
-			'$to' => DI::l10n()->t('To:'),
-			'$subject' => DI::l10n()->t('Subject:'),
-			'$subjtxt' => $message['title'],
-			'$readonly' => ' readonly="readonly" style="background: #BBBBBB;" ',
-			'$yourmessage' => DI::l10n()->t('Your message:'),
-			'$text' => '',
-			'$select' => $select,
-			'$parent' => $parent,
-			'$upload' => DI::l10n()->t('Upload photo'),
-			'$insert' => DI::l10n()->t('Insert web link'),
-			'$submit' => DI::l10n()->t('Submit'),
-			'$wait' => DI::l10n()->t('Please wait')
+			'$header'         => DI::l10n()->t('Send Reply'),
+			'$to'             => DI::l10n()->t('To:'),
+			'$subject'        => DI::l10n()->t('Subject:'),
+			'$subjtxt'        => $message['title'],
+			'$readonly'       => ' readonly="readonly" style="background: #BBBBBB;" ',
+			'$yourmessage'    => DI::l10n()->t('Your message:'),
+			'$text'           => '',
+			'$select'         => $select,
+			'$parent'         => $parent,
+			'$upload'         => DI::l10n()->t('Upload photo'),
+			'$insert'         => DI::l10n()->t('Insert web link'),
+			'$submit'         => DI::l10n()->t('Submit'),
+			'$wait'           => DI::l10n()->t('Please wait')
 		]);
 
 		return $o;
@@ -368,7 +370,7 @@ function message_content(App $a)
  * @param int $limit
  * @return array
  */
-function get_messages(int $uid, int $start, int $limit)
+function get_messages(int $uid, int $start, int $limit): array
 {
 	return DBA::toArray(DBA::p('SELECT
 			m.`id`,
@@ -392,21 +394,21 @@ function get_messages(int $uid, int $start, int $limit)
 			c.`url`,
 			c.`thumb`,
 			c.`network`,
-       		m2.`count`,
-       		m2.`mailcreated`,
-       		m2.`mailseen`
-       	FROM `mail` m
-       	JOIN (
-       		SELECT
-       			`parent-uri`,
-       		    MIN(`id`)      AS `id`,
-       		    COUNT(*)       AS `count`,
-       		    MAX(`created`) AS `mailcreated`,
-       		    MIN(`seen`)    AS `mailseen`
-       		FROM `mail`
-       		WHERE `uid` = ?
-       		GROUP BY `parent-uri`
-       	) m2 ON m.`parent-uri` = m2.`parent-uri` AND m.`id` = m2.`id`
+			m2.`count`,
+			m2.`mailcreated`,
+			m2.`mailseen`
+		FROM `mail` m
+		JOIN (
+			SELECT
+				`parent-uri`,
+				MIN(`id`)      AS `id`,
+				COUNT(*)       AS `count`,
+				MAX(`created`) AS `mailcreated`,
+				MIN(`seen`)    AS `mailseen`
+			FROM `mail`
+			WHERE `uid` = ?
+			GROUP BY `parent-uri`
+		) m2 ON m.`parent-uri` = m2.`parent-uri` AND m.`id` = m2.`id`
 		LEFT JOIN `contact` c ON m.`contact-id` = c.`id`
 		WHERE m.`uid` = ?
 		ORDER BY m2.`mailcreated` DESC
@@ -414,7 +416,7 @@ function get_messages(int $uid, int $start, int $limit)
 		, $uid, $uid, $start, $limit));
 }
 
-function render_messages(array $msg, $t)
+function render_messages(array $msg, string $t): string
 {
 	$a = DI::app();
 
@@ -444,20 +446,20 @@ function render_messages(array $msg, $t)
 		$from_photo = Contact::getThumb($contact);
 
 		$rslt .= Renderer::replaceMacros($tpl, [
-			'$id' => $rr['id'],
-			'$from_name' => $participants,
-			'$from_url' => Contact::magicLink($rr['url']),
-			'$from_addr' => $contact['addr'] ?? '',
-			'$sparkle' => ' sparkle',
+			'$id'         => $rr['id'],
+			'$from_name'  => $participants,
+			'$from_url'   => Contact::magicLink($rr['url']),
+			'$from_addr'  => $contact['addr'] ?? '',
+			'$sparkle'    => ' sparkle',
 			'$from_photo' => $from_photo,
-			'$subject' => $rr['title'],
-			'$delete' => DI::l10n()->t('Delete conversation'),
-			'$body' => $body_e,
-			'$to_name' => $to_name_e,
-			'$date' => DateTimeFormat::local($rr['mailcreated'], DI::l10n()->t('D, d M Y - g:i A')),
-			'$ago' => Temporal::getRelativeDate($rr['mailcreated']),
-			'$seen' => $rr['mailseen'],
-			'$count' => DI::l10n()->tt('%d message', '%d messages', $rr['count']),
+			'$subject'    => $rr['title'],
+			'$delete'     => DI::l10n()->t('Delete conversation'),
+			'$body'       => $body_e,
+			'$to_name'    => $to_name_e,
+			'$date'       => DateTimeFormat::local($rr['mailcreated'], DI::l10n()->t('D, d M Y - g:i A')),
+			'$ago'        => Temporal::getRelativeDate($rr['mailcreated']),
+			'$seen'       => $rr['mailseen'],
+			'$count'      => DI::l10n()->tt('%d message', '%d messages', $rr['count']),
 		]);
 	}
 
diff --git a/mod/notes.php b/mod/notes.php
index a30d807693..2c23e7aaa6 100644
--- a/mod/notes.php
+++ b/mod/notes.php
@@ -38,7 +38,7 @@ function notes_init(App $a)
 }
 
 
-function notes_content(App $a, $update = false)
+function notes_content(App $a, bool $update = false)
 {
 	if (!local_user()) {
 		DI::sysmsg()->addNotice(DI::l10n()->t('Permission denied.'));
@@ -60,7 +60,7 @@ function notes_content(App $a, $update = false)
 		$o .= DI::conversation()->statusEditor($x, $a->getContactId());
 	}
 
-	$condition = ['uid' => local_user(), 'post-type' => Item::PT_PERSONAL_NOTE, 'gravity' => GRAVITY_PARENT,
+	$condition = ['uid' => local_user(), 'post-type' => Item::PT_PERSONAL_NOTE, 'gravity' => Item::GRAVITY_PARENT,
 		'contact-id'=> $a->getContactId()];
 
 	if (DI::mode()->isMobile()) {
diff --git a/mod/oexchange.php b/mod/oexchange.php
index 173de0a6bc..f914e1e177 100644
--- a/mod/oexchange.php
+++ b/mod/oexchange.php
@@ -20,6 +20,8 @@
  */
 
 use Friendica\App;
+use Friendica\Content\Text\BBCode;
+use Friendica\Content\Text\HTML;
 use Friendica\Core\System;
 use Friendica\DI;
 use Friendica\Module\Response;
@@ -93,8 +95,8 @@ function oexchange_init(App $a)
 	System::httpExit($xml->saveXML(), Response::TYPE_XML, 'application/xrd+xml');
 }
 
-function oexchange_content(App $a) {
-
+function oexchange_content(App $a)
+{
 	if (!local_user()) {
 		$o = Login::form();
 		return $o;
@@ -109,7 +111,7 @@ function oexchange_content(App $a) {
 	$description = !empty($_REQUEST['description']) ? trim($_REQUEST['description']) : '';
 	$tags        = !empty($_REQUEST['tags'])        ? trim($_REQUEST['tags'])        : '';
 
-	$s = \Friendica\Content\Text\BBCode::embedURL($url, true, $title, $description, $tags);
+	$s = BBCode::embedURL($url, true, $title, $description, $tags);
 
 	if (!strlen($s)) {
 		return;
@@ -119,9 +121,9 @@ function oexchange_content(App $a) {
 
 	$post['profile_uid'] = local_user();
 	$post['return'] = '/oexchange/done';
-	$post['body'] = Friendica\Content\Text\HTML::toBBCode($s);
+	$post['body'] = HTML::toBBCode($s);
 
 	$_REQUEST = $post;
-	require_once('mod/item.php');
+	require_once 'mod/item.php';
 	item_post($a);
 }
diff --git a/mod/ostatus_subscribe.php b/mod/ostatus_subscribe.php
index 2ecea60166..0dbce59f29 100644
--- a/mod/ostatus_subscribe.php
+++ b/mod/ostatus_subscribe.php
@@ -27,7 +27,7 @@ use Friendica\Model\Contact;
 use Friendica\Network\HTTPClient\Client\HttpClientAccept;
 use Friendica\Protocol\ActivityPub;
 
-function ostatus_subscribe_content(App $a)
+function ostatus_subscribe_content(App $a): string
 {
 	if (!local_user()) {
 		DI::sysmsg()->addNotice(DI::l10n()->t('Permission denied.'));
@@ -42,7 +42,6 @@ function ostatus_subscribe_content(App $a)
 	$counter = intval($_REQUEST['counter'] ?? 0);
 
 	if (DI::pConfig()->get($uid, 'ostatus', 'legacy_friends') == '') {
-
 		if ($_REQUEST['url'] == '') {
 			DI::pConfig()->delete($uid, 'ostatus', 'legacy_contact');
 			return $o . DI::l10n()->t('No contact provided.');
diff --git a/mod/photos.php b/mod/photos.php
index 047328aa53..8111fffa30 100644
--- a/mod/photos.php
+++ b/mod/photos.php
@@ -55,8 +55,8 @@ use Friendica\Util\Temporal;
 use Friendica\Util\XML;
 use Friendica\Network\HTTPException;
 
-function photos_init(App $a) {
-
+function photos_init(App $a)
+{
 	if (DI::config()->get('system', 'block_public') && !Session::isAuthenticated()) {
 		return;
 	}
@@ -526,44 +526,40 @@ function photos_post(App $a)
 				foreach ($taginfo as $tagged) {
 					$uri = Item::newURI();
 
-					$arr = [];
-					$arr['guid']          = System::createUUID();
-					$arr['uid']           = $page_owner_uid;
-					$arr['uri']           = $uri;
-					$arr['wall']          = 1;
-					$arr['contact-id']    = $owner_record['id'];
-					$arr['owner-name']    = $owner_record['name'];
-					$arr['owner-link']    = $owner_record['url'];
-					$arr['owner-avatar']  = $owner_record['thumb'];
-					$arr['author-name']   = $owner_record['name'];
-					$arr['author-link']   = $owner_record['url'];
-					$arr['author-avatar'] = $owner_record['thumb'];
-					$arr['title']         = '';
-					$arr['allow_cid']     = $photo['allow_cid'];
-					$arr['allow_gid']     = $photo['allow_gid'];
-					$arr['deny_cid']      = $photo['deny_cid'];
-					$arr['deny_gid']      = $photo['deny_gid'];
-					$arr['visible']       = 0;
-					$arr['verb']          = Activity::TAG;
-					$arr['gravity']       = GRAVITY_PARENT;
-					$arr['object-type']   = Activity\ObjectType::PERSON;
-					$arr['target-type']   = Activity\ObjectType::IMAGE;
-					$arr['inform']        = $tagged[2];
-					$arr['origin']        = 1;
-					$arr['body']          = DI::l10n()->t('%1$s was tagged in %2$s by %3$s', '[url=' . $tagged[1] . ']' . $tagged[0] . '[/url]', '[url=' . DI::baseUrl() . '/photos/' . $owner_record['nickname'] . '/image/' . $photo['resource-id'] . ']' . DI::l10n()->t('a photo') . '[/url]', '[url=' . $owner_record['url'] . ']' . $owner_record['name'] . '[/url]') ;
-					$arr['body'] .= "\n\n" . '[url=' . DI::baseUrl() . '/photos/' . $owner_record['nickname'] . '/image/' . $photo['resource-id'] . ']' . '[img]' . DI::baseUrl() . "/photo/" . $photo['resource-id'] . '-' . $best . '.' . $ext . '[/img][/url]' . "\n" ;
+					$arr = [
+						'guid'          => System::createUUID(),
+						'uid'           => $page_owner_uid,
+						'uri'           => $uri,
+						'wall'          => 1,
+						'contact-id'    => $owner_record['id'],
+						'owner-name'    => $owner_record['name'],
+						'owner-link'    => $owner_record['url'],
+						'owner-avatar'  => $owner_record['thumb'],
+						'author-name'   => $owner_record['name'],
+						'author-link'   => $owner_record['url'],
+						'author-avatar' => $owner_record['thumb'],
+						'title'         => '',
+						'allow_cid'     => $photo['allow_cid'],
+						'allow_gid'     => $photo['allow_gid'],
+						'deny_cid'      => $photo['deny_cid'],
+						'deny_gid'      => $photo['deny_gid'],
+						'visible'       => 0,
+						'verb'          => Activity::TAG,
+						'gravity'       => Item::GRAVITY_PARENT,
+						'object-type'   => Activity\ObjectType::PERSON,
+						'target-type'   => Activity\ObjectType::IMAGE,
+						'inform'        => $tagged[2],
+						'origin'        => 1,
+						'body'          => DI::l10n()->t('%1$s was tagged in %2$s by %3$s', '[url=' . $tagged[1] . ']' . $tagged[0] . '[/url]', '[url=' . DI::baseUrl() . '/photos/' . $owner_record['nickname'] . '/image/' . $photo['resource-id'] . ']' . DI::l10n()->t('a photo') . '[/url]', '[url=' . $owner_record['url'] . ']' . $owner_record['name'] . '[/url]') . "\n\n" . '[url=' . DI::baseUrl() . '/photos/' . $owner_record['nickname'] . '/image/' . $photo['resource-id'] . ']' . '[img]' . DI::baseUrl() . '/photo/' . $photo['resource-id'] . '-' . $best . '.' . $ext . '[/img][/url]' . "\n",
+						'object'        => '<object><type>' . Activity\ObjectType::PERSON . '</type><title>' . $tagged[0] . '</title><id>' . $tagged[1] . '/' . $tagged[0] . '</id><link>' . XML::escape('<link rel="alternate" type="text/html" href="' . $tagged[1] . '" />' . "\n"),
+						'target'        => '<target><type>' . Activity\ObjectType::IMAGE . '</type><title>' . $photo['desc'] . '</title><id>' . DI::baseUrl() . '/photos/' . $owner_record['nickname'] . '/image/' . $photo['resource-id'] . '</id><link>' . XML::escape('<link rel="alternate" type="text/html" href="' . DI::baseUrl() . '/photos/' . $owner_record['nickname'] . '/image/' . $photo['resource-id'] . '" />' . "\n" . '<link rel="preview" type="' . $photo['type'] . '" href="' . DI::baseUrl() . '/photo/' . $photo['resource-id'] . '-' . $best . '.' . $ext . '" />') . '</link></target>',
+					];
 
-					$arr['object'] = '<object><type>' . Activity\ObjectType::PERSON . '</type><title>' . $tagged[0] . '</title><id>' . $tagged[1] . '/' . $tagged[0] . '</id>';
-					$arr['object'] .= '<link>' . XML::escape('<link rel="alternate" type="text/html" href="' . $tagged[1] . '" />' . "\n");
 					if ($tagged[3]) {
 						$arr['object'] .= XML::escape('<link rel="photo" type="' . $photo['type'] . '" href="' . $tagged[3]['photo'] . '" />' . "\n");
 					}
 					$arr['object'] .= '</link></object>' . "\n";
 
-					$arr['target'] = '<target><type>' . Activity\ObjectType::IMAGE . '</type><title>' . $photo['desc'] . '</title><id>'
-						. DI::baseUrl() . '/photos/' . $owner_record['nickname'] . '/image/' . $photo['resource-id'] . '</id>';
-					$arr['target'] .= '<link>' . XML::escape('<link rel="alternate" type="text/html" href="' . DI::baseUrl() . '/photos/' . $owner_record['nickname'] . '/image/' . $photo['resource-id'] . '" />' . "\n" . '<link rel="preview" type="' . $photo['type'] . '" href="' . DI::baseUrl() . "/photo/" . $photo['resource-id'] . '-' . $best . '.' . $ext . '" />') . '</link></target>';
-
 					Item::insert($arr);
 				}
 			}
@@ -1233,7 +1229,7 @@ function photos_content(App $a)
 		$link_item = Post::selectFirst([], ["`resource-id` = ?" . $sql_extra, $datum]);
 
 		if (!empty($link_item['parent']) && !empty($link_item['uid'])) {
-			$condition = ["`parent` = ? AND `gravity` = ?",  $link_item['parent'], GRAVITY_COMMENT];
+			$condition = ["`parent` = ? AND `gravity` = ?",  $link_item['parent'], Item::GRAVITY_COMMENT];
 			$total = Post::count($condition);
 
 			$pager = new Pager(DI::l10n(), DI::args()->getQueryString());
@@ -1404,7 +1400,7 @@ function photos_content(App $a)
 
 					if (($activity->match($item['verb'], Activity::LIKE) ||
 					     $activity->match($item['verb'], Activity::DISLIKE)) &&
-					    ($item['gravity'] != GRAVITY_PARENT)) {
+					    ($item['gravity'] != Item::GRAVITY_PARENT)) {
 						continue;
 					}
 
@@ -1421,25 +1417,25 @@ function photos_content(App $a)
 					$drop = [
 						'dropping' => $dropping,
 						'pagedrop' => false,
-						'select' => DI::l10n()->t('Select'),
-						'delete' => DI::l10n()->t('Delete'),
+						'select'   => DI::l10n()->t('Select'),
+						'delete'   => DI::l10n()->t('Delete'),
 					];
 
 					$title_e = $item['title'];
 					$body_e = BBCode::convertForUriId($item['uri-id'], $item['body']);
 
 					$comments .= Renderer::replaceMacros($template,[
-						'$id' => $item['id'],
+						'$id'          => $item['id'],
 						'$profile_url' => $profile_url,
-						'$name' => $item['author-name'],
-						'$thumb' => $item['author-avatar'],
-						'$sparkle' => $sparkle,
-						'$title' => $title_e,
-						'$body' => $body_e,
-						'$ago' => Temporal::getRelativeDate($item['created']),
-						'$indent' => (($item['parent'] != $item['id']) ? ' comment' : ''),
-						'$drop' => $drop,
-						'$comment' => $comment
+						'$name'        => $item['author-name'],
+						'$thumb'       => $item['author-avatar'],
+						'$sparkle'     => $sparkle,
+						'$title'       => $title_e,
+						'$body'        => $body_e,
+						'$ago'         => Temporal::getRelativeDate($item['created']),
+						'$indent'      => (($item['parent'] != $item['id']) ? ' comment' : ''),
+						'$drop'        => $drop,
+						'$comment'     => $comment
 					]);
 
 					if (($can_post || Security::canWriteToUserWall($owner_uid))) {
diff --git a/mod/tagger.php b/mod/tagger.php
index 45b743166c..b3f5f9af19 100644
--- a/mod/tagger.php
+++ b/mod/tagger.php
@@ -35,8 +35,8 @@ use Friendica\Protocol\Activity;
 use Friendica\Util\XML;
 use Friendica\Worker\Delivery;
 
-function tagger_content(App $a) {
-
+function tagger_content(App $a)
+{
 	if (!Session::isAuthenticated()) {
 		return;
 	}
@@ -116,41 +116,41 @@ EOT;
 
 	$termlink = html_entity_decode('&#x2317;') . '[url=' . DI::baseUrl() . '/search?tag=' . $term . ']'. $term . '[/url]';
 
-	$arr = [];
-
-	$arr['guid'] = System::createUUID();
-	$arr['uri'] = $uri;
-	$arr['uid'] = $owner_uid;
-	$arr['contact-id'] = $contact['id'];
-	$arr['wall'] = $item['wall'];
-	$arr['gravity'] = GRAVITY_COMMENT;
-	$arr['parent'] = $item['id'];
-	$arr['thr-parent'] = $item['uri'];
-	$arr['owner-name'] = $item['author-name'];
-	$arr['owner-link'] = $item['author-link'];
-	$arr['owner-avatar'] = $item['author-avatar'];
-	$arr['author-name'] = $contact['name'];
-	$arr['author-link'] = $contact['url'];
-	$arr['author-avatar'] = $contact['thumb'];
-
 	$ulink = '[url=' . $contact['url'] . ']' . $contact['name'] . '[/url]';
 	$alink = '[url=' . $item['author-link'] . ']' . $item['author-name'] . '[/url]';
 	$plink = '[url=' . $item['plink'] . ']' . $post_type . '[/url]';
-	$arr['body'] =  sprintf( $bodyverb, $ulink, $alink, $plink, $termlink );
 
-	$arr['verb'] = Activity::TAG;
-	$arr['target-type'] = $targettype;
-	$arr['target'] = $target;
-	$arr['object-type'] = $objtype;
-	$arr['object'] = $obj;
-	$arr['private'] = $item['private'];
-	$arr['allow_cid'] = $item['allow_cid'];
-	$arr['allow_gid'] = $item['allow_gid'];
-	$arr['deny_cid'] = $item['deny_cid'];
-	$arr['deny_gid'] = $item['deny_gid'];
-	$arr['visible'] = 1;
-	$arr['unseen'] = 1;
-	$arr['origin'] = 1;
+	$arr = [
+		'guid'          => System::createUUID(),
+		'uri'           => $uri,
+		'uid'           => $owner_uid,
+		'contact-id'    => $contact['id'],
+		'wall'          => $item['wall'],
+		'gravity'       => Item::GRAVITY_COMMENT,
+		'parent'        => $item['id'],
+		'thr-parent'    => $item['uri'],
+		'owner-name'    => $item['author-name'],
+		'owner-link'    => $item['author-link'],
+		'owner-avatar'  => $item['author-avatar'],
+		'author-name'   => $contact['name'],
+		'author-link'   => $contact['url'],
+		'author-avatar' => $contact['thumb'],
+		'body'          => sprintf($bodyverb, $ulink, $alink, $plink, $termlink),
+		'verb'          => Activity::TAG,
+		'target-type'   => $targettype,
+		'target'        => $target,
+		'object-type'   => $objtype,
+		'object'        => $obj,
+		'private'       => $item['private'],
+		'allow_cid'     => $item['allow_cid'],
+		'allow_gid'     => $item['allow_gid'],
+		'deny_cid'      => $item['deny_cid'],
+		'deny_gid'      => $item['deny_gid'],
+		'visible'       => 1,
+		'unseen'        => 1,
+		'origin'        => 1,
+	];
+
 
 	$post_id = Item::insert($arr);
 
diff --git a/src/Content/Conversation.php b/src/Content/Conversation.php
index a381828497..817bc402a8 100644
--- a/src/Content/Conversation.php
+++ b/src/Content/Conversation.php
@@ -135,7 +135,7 @@ class Conversation
 					return;
 			}
 
-			if (!empty($activity['verb']) && $this->activity->match($activity['verb'], $verb) && ($activity['gravity'] != GRAVITY_PARENT)) {
+			if (!empty($activity['verb']) && $this->activity->match($activity['verb'], $verb) && ($activity['gravity'] != ItemModel::GRAVITY_PARENT)) {
 				$author = [
 					'uid'     => 0,
 					'id'      => $activity['author-id'],
@@ -756,7 +756,7 @@ class Conversation
 
 					$item['pagedrop'] = $page_dropping;
 
-					if ($item['gravity'] == GRAVITY_PARENT) {
+					if ($item['gravity'] == ItemModel::GRAVITY_PARENT) {
 						$item_object = new PostObject($item);
 						$conv->addParent($item_object);
 					}
@@ -826,7 +826,7 @@ class Conversation
 		}
 
 		if (!empty($activity)) {
-			if (($row['gravity'] == GRAVITY_PARENT)) {
+			if (($row['gravity'] == ItemModel::GRAVITY_PARENT)) {
 				$row['post-reason'] = ItemModel::PR_ANNOUNCEMENT;
 
 				$row     = array_merge($row, $activity);
@@ -835,7 +835,7 @@ class Conversation
 				$row['causer-link']   = $contact['url'];
 				$row['causer-avatar'] = $contact['thumb'];
 				$row['causer-name']   = $contact['name'];
-			} elseif (($row['gravity'] == GRAVITY_ACTIVITY) && ($row['verb'] == Activity::ANNOUNCE) &&
+			} elseif (($row['gravity'] == ItemModel::GRAVITY_ACTIVITY) && ($row['verb'] == Activity::ANNOUNCE) &&
 				($row['author-id'] == $activity['causer-id'])) {
 				return $row;
 			}
@@ -868,7 +868,7 @@ class Conversation
 					$row['owner-name']   = $row['causer-name'];
 				}
 
-				if (in_array($row['gravity'], [GRAVITY_PARENT, GRAVITY_COMMENT]) && !empty($row['causer-id'])) {
+				if (in_array($row['gravity'], [ItemModel::GRAVITY_PARENT, ItemModel::GRAVITY_COMMENT]) && !empty($row['causer-id'])) {
 					$causer = ['uid' => 0, 'id' => $row['causer-id'], 'network' => $row['causer-network'], 'url' => $row['causer-link']];
 
 					$row['reshared'] = $this->l10n->t('%s reshared this.', '<a href="'. htmlentities(Contact::magicLinkByContact($causer)) .'">' . htmlentities($row['causer-name']) . '</a>');
@@ -942,7 +942,7 @@ class Conversation
 		$activitycounter = [];
 
 		foreach ($parents as $parent) {
-			if (!empty($parent['thr-parent-id']) && !empty($parent['gravity']) && ($parent['gravity'] == GRAVITY_ACTIVITY)) {
+			if (!empty($parent['thr-parent-id']) && !empty($parent['gravity']) && ($parent['gravity'] == ItemModel::GRAVITY_ACTIVITY)) {
 				$uriid = $parent['thr-parent-id'];
 				if (!empty($parent['author-id'])) {
 					$activities[$uriid] = ['causer-id' => $parent['author-id']];
@@ -994,10 +994,10 @@ class Conversation
 			}
 
 			if ($max_comments > 0) {
-				if (($row['gravity'] == GRAVITY_COMMENT) && (++$commentcounter[$row['parent-uri-id']] > $max_comments)) {
+				if (($row['gravity'] == ItemModel::GRAVITY_COMMENT) && (++$commentcounter[$row['parent-uri-id']] > $max_comments)) {
 					continue;
 				}
-				if (($row['gravity'] == GRAVITY_ACTIVITY) && (++$activitycounter[$row['parent-uri-id']] > $max_comments)) {
+				if (($row['gravity'] == ItemModel::GRAVITY_ACTIVITY) && (++$activitycounter[$row['parent-uri-id']] > $max_comments)) {
 					continue;
 				}
 			}
@@ -1026,7 +1026,7 @@ class Conversation
 		$this->profiler->startRecording('rendering');
 		$children = [];
 		foreach ($item_list as $i => $item) {
-			if ($item['gravity'] != GRAVITY_PARENT) {
+			if ($item['gravity'] != ItemModel::GRAVITY_PARENT) {
 				if ($recursive) {
 					// Fallback to parent-uri if thr-parent is not set
 					$thr_parent = $item['thr-parent-id'];
@@ -1183,7 +1183,7 @@ class Conversation
 
 		// Extract the top level items
 		foreach ($item_array as $item) {
-			if ($item['gravity'] == GRAVITY_PARENT) {
+			if ($item['gravity'] == ItemModel::GRAVITY_PARENT) {
 				$parents[] = $item;
 			}
 		}
diff --git a/src/Content/Item.php b/src/Content/Item.php
index bfa107325c..80edecc821 100644
--- a/src/Content/Item.php
+++ b/src/Content/Item.php
@@ -31,7 +31,7 @@ use Friendica\Core\System;
 use Friendica\Database\DBA;
 use Friendica\Model\Contact;
 use Friendica\Model\Group;
-use Friendica\Model\Item as ModelItem;
+use Friendica\Model\Item as ItemModel;
 use Friendica\Model\Photo;
 use Friendica\Model\Tag;
 use Friendica\Model\Post;
@@ -331,7 +331,7 @@ class Item
 		$sub_link = $contact_url = $pm_url = $status_link = '';
 		$photos_link = $posts_link = $block_link = $ignore_link = '';
 
-		if (local_user() && local_user() == $item['uid'] && $item['gravity'] == GRAVITY_PARENT && !$item['self'] && !$item['mention']) {
+		if (local_user() && local_user() == $item['uid'] && $item['gravity'] == ItemModel::GRAVITY_PARENT && !$item['self'] && !$item['mention']) {
 			$sub_link = 'javascript:doFollowThread(' . $item['id'] . '); return false;';
 		}
 
@@ -392,7 +392,7 @@ class Item
 			];
 
 			if (!empty($item['language'])) {
-				$menu[$this->l10n->t('Languages')] = 'javascript:alert(\'' . ModelItem::getLanguageMessage($item) . '\');';
+				$menu[$this->l10n->t('Languages')] = 'javascript:alert(\'' . ItemModel::getLanguageMessage($item) . '\');';
 			}
 
 			if ((($cid == 0) || ($rel == Contact::FOLLOWER)) &&
@@ -470,7 +470,7 @@ class Item
 			}
 			$item['inform'] .= 'cid:' . $contact['id'];
 
-			if (($item['gravity'] == GRAVITY_COMMENT) || empty($contact['cid']) || ($contact['contact-type'] != Contact::TYPE_COMMUNITY)) {
+			if (($item['gravity'] == ItemModel::GRAVITY_COMMENT) || empty($contact['cid']) || ($contact['contact-type'] != Contact::TYPE_COMMUNITY)) {
 				continue;
 			}
 
@@ -492,9 +492,9 @@ class Item
 		}
 		Logger::info('Got inform', ['inform' => $item['inform']]);
 
-		if (($item['gravity'] == GRAVITY_PARENT) && !empty($forum_contact) && ($private_forum || $only_to_forum)) {
+		if (($item['gravity'] == ItemModel::GRAVITY_PARENT) && !empty($forum_contact) && ($private_forum || $only_to_forum)) {
 			// we tagged a forum in a top level post. Now we change the post
-			$item['private'] = $private_forum ? ModelItem::PRIVATE : ModelItem::UNLISTED;
+			$item['private'] = $private_forum ? ItemModel::PRIVATE : ItemModel::UNLISTED;
 
 			if ($only_to_forum) {
 				$item['postopts'] = '';
@@ -510,14 +510,14 @@ class Item
 				$item['allow_cid'] = '';
 				$item['allow_gid'] = '';
 			}
-		} elseif ($setPermissions && ($item['gravity'] == GRAVITY_PARENT)) {
+		} elseif ($setPermissions && ($item['gravity'] == ItemModel::GRAVITY_PARENT)) {
 			if (empty($receivers)) {
 				// For security reasons direct posts without any receiver will be posts to yourself
 				$self = Contact::selectFirst(['id'], ['uid' => $item['uid'], 'self' => true]);
 				$receivers[] = $self['id'];
 			}
 
-			$item['private']   = ModelItem::PRIVATE;
+			$item['private']   = ItemModel::PRIVATE;
 			$item['allow_cid'] = '';
 			$item['allow_gid'] = '';
 			$item['deny_cid']  = '';
diff --git a/src/Core/Protocol.php b/src/Core/Protocol.php
index c141bbc54e..015612adea 100644
--- a/src/Core/Protocol.php
+++ b/src/Core/Protocol.php
@@ -22,6 +22,7 @@
 namespace Friendica\Core;
 
 use Friendica\Database\DBA;
+use Friendica\Model\Item;
 use Friendica\Model\User;
 use Friendica\Network\HTTPException;
 use Friendica\Protocol\Activity;
@@ -139,7 +140,7 @@ class Protocol
 			// create a follow slap
 			$item = [
 				'verb'    => Activity::FOLLOW,
-				'gravity' => GRAVITY_ACTIVITY,
+				'gravity' => Item::GRAVITY_ACTIVITY,
 				'follow'  => $contact['url'],
 				'body'    => '',
 				'title'   => '',
@@ -191,14 +192,16 @@ class Protocol
 
 		if (in_array($protocol, [Protocol::OSTATUS, Protocol::DFRN])) {
 			// create an unfollow slap
-			$item = [];
-			$item['verb'] = Activity::O_UNFOLLOW;
-			$item['gravity'] = GRAVITY_ACTIVITY;
-			$item['follow'] = $contact['url'];
-			$item['body'] = '';
-			$item['title'] = '';
-			$item['guid'] = '';
-			$item['uri-id'] = 0;
+			$item = [
+				'verb'    => Activity::O_UNFOLLOW,
+				'gravity' => Item::GRAVITY_ACTIVITY,
+				'follow'  => $contact['url'],
+				'body'    => '',
+				'title'   => '',
+				'guid'    => '',
+				'uri-id'  => 0,
+			];
+
 			$slap = OStatus::salmon($item, $user);
 
 			if (empty($contact['notify'])) {
diff --git a/src/Core/Renderer.php b/src/Core/Renderer.php
index 879fdfe19e..0a86cc6f86 100644
--- a/src/Core/Renderer.php
+++ b/src/Core/Renderer.php
@@ -48,19 +48,19 @@ class Renderer
 	 * beyond are used.
 	 */
 	public static $theme = [
-		'videowidth' => 425,
-		'videoheight' => 350,
-		'stylesheet' => '',
+		'videowidth'      => 425,
+		'videoheight'     => 350,
+		'stylesheet'      => '',
 		'template_engine' => 'smarty3',
 	];
 
 	private static $ldelim = [
 		'internal' => '',
-		'smarty3' => '{{'
+		'smarty3'  => '{{'
 	];
 	private static $rdelim = [
 		'internal' => '',
-		'smarty3' => '}}'
+		'smarty3'  => '}}'
 	];
 
 	/**
@@ -101,10 +101,10 @@ class Renderer
 	 * @param string $file   Template to load.
 	 * @param string $subDir Subdirectory (Optional)
 	 *
-	 * @return string template.
+	 * @return string Template
 	 * @throws ServiceUnavailableException
 	 */
-	public static function getMarkupTemplate($file, $subDir = '')
+	public static function getMarkupTemplate(string $file, string $subDir = ''): string
 	{
 		DI::profiler()->startRecording('file');
 		$t = self::getTemplateEngine();
@@ -128,9 +128,11 @@ class Renderer
 	 * Register template engine class
 	 *
 	 * @param string $class
+	 *
+	 * @return void
 	 * @throws ServiceUnavailableException
 	 */
-	public static function registerTemplateEngine($class)
+	public static function registerTemplateEngine(string $class)
 	{
 		$v = get_class_vars($class);
 
@@ -156,7 +158,7 @@ class Renderer
 	 * @return TemplateEngine Template Engine instance
 	 * @throws ServiceUnavailableException
 	 */
-	public static function getTemplateEngine()
+	public static function getTemplateEngine(): TemplateEngine
 	{
 		$template_engine = (self::$theme['template_engine'] ?? '') ?: 'smarty3';
 
@@ -185,7 +187,7 @@ class Renderer
 	 *
 	 * @return string the active template engine
 	 */
-	public static function getActiveTemplateEngine()
+	public static function getActiveTemplateEngine(): string
 	{
 		return self::$theme['template_engine'];
 	}
@@ -194,8 +196,10 @@ class Renderer
 	 * sets the active template engine
 	 *
 	 * @param string $engine the template engine (default is Smarty3)
+	 *
+	 * @return void
 	 */
-	public static function setActiveTemplateEngine($engine = 'smarty3')
+	public static function setActiveTemplateEngine(string $engine = 'smarty3')
 	{
 		self::$theme['template_engine'] = $engine;
 	}
@@ -211,7 +215,7 @@ class Renderer
 	 *
 	 * @return string the right delimiter
 	 */
-	public static function getTemplateLeftDelimiter($engine = 'smarty3')
+	public static function getTemplateLeftDelimiter(string $engine = 'smarty3'): string
 	{
 		return self::$ldelim[$engine];
 	}
@@ -227,7 +231,7 @@ class Renderer
 	 *
 	 * @return string the left delimiter
 	 */
-	public static function getTemplateRightDelimiter($engine = 'smarty3')
+	public static function getTemplateRightDelimiter(string $engine = 'smarty3'): string
 	{
 		return self::$rdelim[$engine];
 	}
diff --git a/src/Database/PostUpdate.php b/src/Database/PostUpdate.php
index c0eac95c81..04c218ca00 100644
--- a/src/Database/PostUpdate.php
+++ b/src/Database/PostUpdate.php
@@ -563,7 +563,7 @@ class PostUpdate
 		$items = DBA::p("SELECT `item`.`id`, `item`.`verb` AS `item-verb`, `item-content`.`verb`, `item-activity`.`activity`
 			FROM `item` LEFT JOIN `item-content` ON `item-content`.`uri-id` = `item`.`uri-id`
 			LEFT JOIN `item-activity` ON `item-activity`.`uri-id` = `item`.`uri-id` AND `item`.`gravity` = ?
-			WHERE `item`.`id` >= ? AND `item`.`vid` IS NULL ORDER BY `item`.`id` LIMIT 10000", GRAVITY_ACTIVITY, $id);
+			WHERE `item`.`id` >= ? AND `item`.`vid` IS NULL ORDER BY `item`.`id` LIMIT 10000", Item::GRAVITY_ACTIVITY, $id);
 
 		if (DBA::errorNo() != 0) {
 			Logger::error('Database error', ['no' => DBA::errorNo(), 'message' => DBA::errorMessage()]);
diff --git a/src/Factory/Api/Friendica/Activities.php b/src/Factory/Api/Friendica/Activities.php
index 102ae382d4..0793203ad8 100644
--- a/src/Factory/Api/Friendica/Activities.php
+++ b/src/Factory/Api/Friendica/Activities.php
@@ -23,6 +23,7 @@ namespace Friendica\Factory\Api\Friendica;
 
 use Friendica\BaseFactory;
 use Friendica\Database\DBA;
+use Friendica\Model\Item;
 use Friendica\Model\Post;
 use Friendica\Network\HTTPException;
 use Friendica\Protocol\Activity;
@@ -62,7 +63,7 @@ class Activities extends BaseFactory
 			'announce'    => [],
 		];
 
-		$condition = ['uid' => $uid, 'thr-parent-id' => $uriId, 'gravity' => GRAVITY_ACTIVITY];
+		$condition = ['uid' => $uid, 'thr-parent-id' => $uriId, 'gravity' => Item::GRAVITY_ACTIVITY];
 
 		$ret = Post::selectForUser($uid, ['author-id', 'verb'], $condition);
 
diff --git a/src/Factory/Api/Friendica/Photo.php b/src/Factory/Api/Friendica/Photo.php
index dad90d13f1..2621a7830c 100644
--- a/src/Factory/Api/Friendica/Photo.php
+++ b/src/Factory/Api/Friendica/Photo.php
@@ -25,6 +25,7 @@ use Friendica\App\BaseURL;
 use Friendica\BaseFactory;
 use Friendica\Database\DBA;
 use Friendica\Factory\Api\Twitter\Status;
+use Friendica\Model\Item;
 use Friendica\Model\Photo as ModelPhoto;
 use Friendica\Model\Post;
 use Friendica\Network\HTTPException;
@@ -116,7 +117,7 @@ class Photo extends BaseFactory
 
 			// retrieve comments on photo
 			$condition = ["`parent` = ? AND `uid` = ? AND `gravity` IN (?, ?)",
-				$item['parent'], $uid, GRAVITY_PARENT, GRAVITY_COMMENT];
+				$item['parent'], $uid, Item::GRAVITY_PARENT, Item::GRAVITY_COMMENT];
 
 			$statuses = Post::selectForUser($uid, [], $condition);
 
diff --git a/src/Factory/Api/Mastodon/ScheduledStatus.php b/src/Factory/Api/Mastodon/ScheduledStatus.php
index 83c1156b22..0195498544 100644
--- a/src/Factory/Api/Mastodon/ScheduledStatus.php
+++ b/src/Factory/Api/Mastodon/ScheduledStatus.php
@@ -24,6 +24,7 @@ namespace Friendica\Factory\Api\Mastodon;
 use Friendica\BaseFactory;
 use Friendica\Database\Database;
 use Friendica\DI;
+use Friendica\Model\Item;
 use Friendica\Model\ItemURI;
 use Friendica\Model\Photo;
 use Friendica\Model\Post;
@@ -69,7 +70,7 @@ class ScheduledStatus extends BaseFactory
 			$media_attachments[] = DI::mstdnAttachment()->createFromPhoto($id);
 		}
 
-		if (isset($parameters['item']['thr-parent']) && ($parameters['item']['gravity'] ?? GRAVITY_PARENT != GRAVITY_PARENT)) {
+		if (isset($parameters['item']['thr-parent']) && ($parameters['item']['gravity'] ?? Item::GRAVITY_PARENT != Item::GRAVITY_PARENT)) {
 			$in_reply_to_id = ItemURI::getIdByURI($parameters['item']['thr-parent']);
 		} else {
 			$in_reply_to_id = null;
diff --git a/src/Factory/Api/Mastodon/Status.php b/src/Factory/Api/Mastodon/Status.php
index 0cce6cb037..21ecee0f95 100644
--- a/src/Factory/Api/Mastodon/Status.php
+++ b/src/Factory/Api/Mastodon/Status.php
@@ -26,6 +26,7 @@ use Friendica\Content\ContactSelector;
 use Friendica\Content\Text\BBCode;
 use Friendica\Database\Database;
 use Friendica\Database\DBA;
+use Friendica\Model\Item;
 use Friendica\Model\Post;
 use Friendica\Model\Tag as TagModel;
 use Friendica\Model\Verb;
@@ -94,19 +95,19 @@ class Status extends BaseFactory
 
 		$count_announce = Post::countPosts([
 			'thr-parent-id' => $uriId,
-			'gravity'       => GRAVITY_ACTIVITY,
+			'gravity'       => Item::GRAVITY_ACTIVITY,
 			'vid'           => Verb::getID(Activity::ANNOUNCE),
 			'deleted'       => false
 		], []);
 		$count_like = Post::countPosts([
 			'thr-parent-id' => $uriId,
-			'gravity'       => GRAVITY_ACTIVITY,
+			'gravity'       => Item::GRAVITY_ACTIVITY,
 			'vid'           => Verb::getID(Activity::LIKE),
 			'deleted'       => false
 		], []);
 
 		$counts = new \Friendica\Object\Api\Mastodon\Status\Counts(
-			Post::countPosts(['thr-parent-id' => $uriId, 'gravity' => GRAVITY_COMMENT, 'deleted' => false], []),
+			Post::countPosts(['thr-parent-id' => $uriId, 'gravity' => Item::GRAVITY_COMMENT, 'deleted' => false], []),
 			$count_announce,
 			$count_like
 		);
@@ -115,7 +116,7 @@ class Status extends BaseFactory
 			'thr-parent-id' => $uriId,
 			'uid'           => $uid,
 			'origin'        => true,
-			'gravity'       => GRAVITY_ACTIVITY,
+			'gravity'       => Item::GRAVITY_ACTIVITY,
 			'vid'           => Verb::getID(Activity::LIKE),
 			'deleted'     => false
 		]);
@@ -123,7 +124,7 @@ class Status extends BaseFactory
 			'thr-parent-id' => $uriId,
 			'uid'           => $uid,
 			'origin'        => true,
-			'gravity'       => GRAVITY_ACTIVITY,
+			'gravity'       => Item::GRAVITY_ACTIVITY,
 			'vid'           => Verb::getID(Activity::ANNOUNCE),
 			'deleted'       => false
 		]);
@@ -131,7 +132,7 @@ class Status extends BaseFactory
 			$origin_like,
 			$origin_announce,
 			Post\ThreadUser::getIgnored($uriId, $uid),
-			(bool)($item['starred'] && ($item['gravity'] == GRAVITY_PARENT)),
+			(bool)($item['starred'] && ($item['gravity'] == Item::GRAVITY_PARENT)),
 			$item['featured']
 		);
 
diff --git a/src/Factory/Api/Twitter/Status.php b/src/Factory/Api/Twitter/Status.php
index 123fd3dcf0..a3ced8e58c 100644
--- a/src/Factory/Api/Twitter/Status.php
+++ b/src/Factory/Api/Twitter/Status.php
@@ -128,7 +128,7 @@ class Status extends BaseFactory
 			$owner = $this->twitterUser->createFromContactId($item['owner-id'], $uid, true);
 		}
 
-		$friendica_comments = Post::countPosts(['thr-parent-id' => $item['uri-id'], 'deleted' => false, 'gravity' => GRAVITY_COMMENT]);
+		$friendica_comments = Post::countPosts(['thr-parent-id' => $item['uri-id'], 'deleted' => false, 'gravity' => Item::GRAVITY_COMMENT]);
 
 		$text  = '';
 		$title = '';
@@ -162,7 +162,7 @@ class Status extends BaseFactory
 			'thr-parent-id' => $item['uri-id'],
 			'uid'           => $uid,
 			'origin'        => true,
-			'gravity'       => GRAVITY_ACTIVITY,
+			'gravity'       => Item::GRAVITY_ACTIVITY,
 			'vid'           => Verb::getID(Activity::LIKE),
 			'deleted'       => false
 		]);
diff --git a/src/Factory/Api/Twitter/User.php b/src/Factory/Api/Twitter/User.php
index 6d4b8784ea..d8bd21c29b 100644
--- a/src/Factory/Api/Twitter/User.php
+++ b/src/Factory/Api/Twitter/User.php
@@ -69,7 +69,7 @@ class User extends BaseFactory
 
 		if (!$skip_status) {
 			$post = Post::selectFirstPost(['uri-id'],
-				['author-id' => $publicContact['id'], 'gravity' => [GRAVITY_COMMENT, GRAVITY_PARENT], 'private'  => [Item::PUBLIC, Item::UNLISTED]],
+				['author-id' => $publicContact['id'], 'gravity' => [Item::GRAVITY_COMMENT, Item::GRAVITY_PARENT], 'private'  => [Item::PUBLIC, Item::UNLISTED]],
 				['order' => ['uri-id' => true]]);
 			if (!empty($post['uri-id'])) {
 				$status = $this->status->createFromUriId($post['uri-id'], $uid)->toArray();
diff --git a/src/Model/APContact.php b/src/Model/APContact.php
index 043f33c313..7b49bab8ab 100644
--- a/src/Model/APContact.php
+++ b/src/Model/APContact.php
@@ -28,6 +28,7 @@ use Friendica\Core\Protocol;
 use Friendica\Core\System;
 use Friendica\Database\DBA;
 use Friendica\DI;
+use Friendica\Model\Item;
 use Friendica\Network\HTTPClient\Client\HttpClientAccept;
 use Friendica\Network\HTTPException;
 use Friendica\Network\Probe;
@@ -495,13 +496,13 @@ class APContact
 	private static function getStatusesCount(array $owner): int
 	{
 		$condition = [
-			'private' => [Item::PUBLIC, Item::UNLISTED],
+			'private'        => [Item::PUBLIC, Item::UNLISTED],
 			'author-id'      => Contact::getIdForURL($owner['url'], 0, false),
-			'gravity'        => [GRAVITY_PARENT, GRAVITY_COMMENT],
+			'gravity'        => [Item::GRAVITY_PARENT, Item::GRAVITY_COMMENT],
 			'network'        => Protocol::DFRN,
 			'parent-network' => Protocol::FEDERATED,
 			'deleted'        => false,
-			'visible'        => true
+			'visible'        => true,
 		];
 
 		$count = Post::countPosts($condition);
diff --git a/src/Model/Contact.php b/src/Model/Contact.php
index ca23c09f6e..1a43d140b2 100644
--- a/src/Model/Contact.php
+++ b/src/Model/Contact.php
@@ -1506,10 +1506,10 @@ class Contact
 
 		if ($thread_mode) {
 			$condition = ["((`$contact_field` = ? AND `gravity` = ?) OR (`author-id` = ? AND `gravity` = ? AND `vid` = ? AND `thr-parent-id` = `parent-uri-id`)) AND " . $sql,
-				$cid, GRAVITY_PARENT, $cid, GRAVITY_ACTIVITY, Verb::getID(Activity::ANNOUNCE), local_user()];
+				$cid, Item::GRAVITY_PARENT, $cid, Item::GRAVITY_ACTIVITY, Verb::getID(Activity::ANNOUNCE), local_user()];
 		} else {
 			$condition = ["`$contact_field` = ? AND `gravity` IN (?, ?) AND " . $sql,
-				$cid, GRAVITY_PARENT, GRAVITY_COMMENT, local_user()];
+				$cid, Item::GRAVITY_PARENT, Item::GRAVITY_COMMENT, local_user()];
 		}
 
 		if (!empty($parent)) {
diff --git a/src/Model/FContact.php b/src/Model/FContact.php
index fa21906bc5..e13dcd46c9 100644
--- a/src/Model/FContact.php
+++ b/src/Model/FContact.php
@@ -26,6 +26,7 @@ use Friendica\Core\Protocol;
 use Friendica\Core\Worker;
 use Friendica\Database\DBA;
 use Friendica\DI;
+use Friendica\Model\Item;
 use Friendica\Network\Probe;
 use Friendica\Util\DateTimeFormat;
 use Friendica\Util\Strings;
@@ -105,27 +106,27 @@ class FContact
 
 			$interacted  = DBA::count('contact-relation', ["`cid` = ? AND NOT `follows` AND `last-interaction` > ?", $contact['id'], $last_interaction]);
 			$interacting = DBA::count('contact-relation', ["`relation-cid` = ? AND NOT `follows` AND `last-interaction` > ?", $contact['id'], $last_interaction]);
-			$posts       = DBA::count('post', ['author-id' => $contact['id'], 'gravity' => [GRAVITY_PARENT, GRAVITY_COMMENT]]);
+			$posts       = DBA::count('post', ['author-id' => $contact['id'], 'gravity' => [Item::GRAVITY_PARENT, Item::GRAVITY_COMMENT]]);
 		}
 
 		$fields = [
-			'name' => $arr['name'],
-			'photo' => $arr['photo'],
-			'request' => $arr['request'],
-			'nick' => $arr['nick'],
-			'addr' => strtolower($arr['addr']),
-			'guid' => $arr['guid'],
-			'batch' => $arr['batch'],
-			'notify' => $arr['notify'],
-			'poll' => $arr['poll'],
-			'confirm' => $arr['confirm'],
-			'alias' => $arr['alias'],
-			'pubkey' => $arr['pubkey'],
-			'uri-id' => $uriid,
+			'name'              => $arr['name'],
+			'photo'             => $arr['photo'],
+			'request'           => $arr['request'],
+			'nick'              => $arr['nick'],
+			'addr'              => strtolower($arr['addr']),
+			'guid'              => $arr['guid'],
+			'batch'             => $arr['batch'],
+			'notify'            => $arr['notify'],
+			'poll'              => $arr['poll'],
+			'confirm'           => $arr['confirm'],
+			'alias'             => $arr['alias'],
+			'pubkey'            => $arr['pubkey'],
+			'uri-id'            => $uriid,
 			'interacting_count' => $interacting ?? 0,
-			'interacted_count' => $interacted ?? 0,
-			'post_count' => $posts ?? 0,
-			'updated' => DateTimeFormat::utcNow(),
+			'interacted_count'  => $interacted ?? 0,
+			'post_count'        => $posts ?? 0,
+			'updated'           => DateTimeFormat::utcNow(),
 		];
 
 		if (empty($fcontact['created'])) {
diff --git a/src/Model/Item.php b/src/Model/Item.php
index 130a1c463d..7ca82f7e62 100644
--- a/src/Model/Item.php
+++ b/src/Model/Item.php
@@ -146,6 +146,12 @@ class Item
 	const PRIVATE = 1;
 	const UNLISTED = 2;
 
+	// Item weight for query ordering
+	const GRAVITY_PARENT   = 0;
+	const GRAVITY_ACTIVITY = 3;
+	const GRAVITY_COMMENT  = 6;
+	const GRAVITY_UNKNOWN  = 9;
+
 	/**
 	 * Update existing item entries
 	 *
@@ -356,7 +362,7 @@ class Item
 		Post\DeliveryData::delete($item['uri-id']);
 
 		// If it's the parent of a comment thread, kill all the kids
-		if ($item['gravity'] == GRAVITY_PARENT) {
+		if ($item['gravity'] == self::GRAVITY_PARENT) {
 			self::markForDeletion(['parent' => $item['parent'], 'deleted' => false], $priority);
 		}
 
@@ -463,7 +469,7 @@ class Item
 			}
 		}
 
-		if ($item['gravity'] == GRAVITY_PARENT) {
+		if ($item['gravity'] == self::GRAVITY_PARENT) {
 			if (Contact::isSharingByURL($item['owner-link'], $item['uid'], true)) {
 				$contact_id = Contact::getIdForURL($item['owner-link'], $item['uid']);
 			} else {
@@ -714,7 +720,7 @@ class Item
 			return 0;
 		}
 
-		if ($thread_parent['gravity'] == GRAVITY_PARENT) {
+		if ($thread_parent['gravity'] == Item::GRAVITY_PARENT) {
 			return $uriid;
 		}
 
@@ -791,17 +797,17 @@ class Item
 		if (isset($item['gravity'])) {
 			return intval($item['gravity']);
 		} elseif ($item['parent-uri-id'] === $item['uri-id']) {
-			return GRAVITY_PARENT;
+			return self::GRAVITY_PARENT;
 		} elseif ($activity->match($item['verb'], Activity::POST)) {
-			return GRAVITY_COMMENT;
+			return self::GRAVITY_COMMENT;
 		} elseif ($activity->match($item['verb'], Activity::FOLLOW)) {
-			return GRAVITY_ACTIVITY;
+			return self::GRAVITY_ACTIVITY;
 		} elseif ($activity->match($item['verb'], Activity::ANNOUNCE)) {
-			return GRAVITY_ACTIVITY;
+			return self::GRAVITY_ACTIVITY;
 		}
 
 		Logger::info('Unknown gravity for verb', ['verb' => $item['verb']]);
-		return GRAVITY_UNKNOWN;   // Should not happen
+		return self::GRAVITY_UNKNOWN;   // Should not happen
 	}
 
 	/**
@@ -965,7 +971,7 @@ class Item
 			return 0;
 		}
 
-		if ($item['gravity'] !== GRAVITY_PARENT) {
+		if ($item['gravity'] !== self::GRAVITY_PARENT) {
 			$toplevel_parent = self::getTopLevelParent($item);
 			if (empty($toplevel_parent)) {
 				return 0;
@@ -1185,7 +1191,7 @@ class Item
 
 		Post::insert($item['uri-id'], $item);
 
-		if ($item['gravity'] == GRAVITY_PARENT) {
+		if ($item['gravity'] == self::GRAVITY_PARENT) {
 			Post\Thread::insert($item['uri-id'], $item);
 		}
 
@@ -1194,7 +1200,7 @@ class Item
 		}
 
 		// Create Diaspora signature
-		if ($item['origin'] && empty($item['diaspora_signed_text']) && ($item['gravity'] != GRAVITY_PARENT)) {
+		if ($item['origin'] && empty($item['diaspora_signed_text']) && ($item['gravity'] != self::GRAVITY_PARENT)) {
 			$signed = Diaspora::createCommentSignature($item);
 			if (!empty($signed)) {
 				$item['diaspora_signed_text'] = json_encode($signed);
@@ -1234,7 +1240,7 @@ class Item
 			return 0;
 		}
 
-		if ($item['gravity'] == GRAVITY_PARENT) {
+		if ($item['gravity'] == self::GRAVITY_PARENT) {
 			$item['post-user-id'] = $post_user_id;
 			Post\ThreadUser::insert($item['uri-id'], $item['uid'], $item);
 		}
@@ -1252,7 +1258,7 @@ class Item
 		// update the commented timestamp on the parent
 		if (DI::config()->get('system', 'like_no_comment')) {
 			// Update when it is a comment
-			$update_commented = in_array($posted_item['gravity'], [GRAVITY_PARENT, GRAVITY_COMMENT]);
+			$update_commented = in_array($posted_item['gravity'], [self::GRAVITY_PARENT, self::GRAVITY_COMMENT]);
 		} else {
 			// Update when it isn't a follow or tag verb
 			$update_commented = !in_array($posted_item['verb'], [Activity::FOLLOW, Activity::TAG]);
@@ -1276,7 +1282,7 @@ class Item
 		}
 
 		if ($notify) {
-			if (!\Friendica\Content\Feature::isEnabled($posted_item['uid'], 'explicit_mentions') && ($posted_item['gravity'] == GRAVITY_COMMENT)) {
+			if (!\Friendica\Content\Feature::isEnabled($posted_item['uid'], 'explicit_mentions') && ($posted_item['gravity'] == self::GRAVITY_COMMENT)) {
 				Tag::createImplicitMentions($posted_item['uri-id'], $posted_item['thr-parent-id']);
 			}
 			Hook::callAll('post_local_end', $posted_item);
@@ -1284,7 +1290,7 @@ class Item
 			Hook::callAll('post_remote_end', $posted_item);
 		}
 
-		if ($posted_item['gravity'] === GRAVITY_PARENT) {
+		if ($posted_item['gravity'] === self::GRAVITY_PARENT) {
 			self::addShadow($post_user_id);
 		} else {
 			self::addShadowPost($post_user_id);
@@ -1319,7 +1325,7 @@ class Item
 		}
 
 		// Fill the cache with the rendered content.
-		if (in_array($posted_item['gravity'], [GRAVITY_PARENT, GRAVITY_COMMENT]) && ($posted_item['uid'] == 0)) {
+		if (in_array($posted_item['gravity'], [self::GRAVITY_PARENT, self::GRAVITY_COMMENT]) && ($posted_item['uid'] == 0)) {
 			self::updateDisplayCache($posted_item['uri-id']);
 		}
 
@@ -1335,7 +1341,7 @@ class Item
 	 */
 	public static function getPostReason(array $item): int
 	{
-		$actor = ($item['gravity'] == GRAVITY_PARENT) ? $item['owner-id'] : $item['author-id'];
+		$actor = ($item['gravity'] == self::GRAVITY_PARENT) ? $item['owner-id'] : $item['author-id'];
 		if (empty($item['origin']) && ($item['uid'] != 0) && Contact::isSharing($actor, $item['uid'])) {
 			return self::PR_FOLLOWER;
 		}
@@ -1416,7 +1422,7 @@ class Item
 	 */
 	private static function distributeByTags(array $item)
 	{
-		if (($item['uid'] != 0) || ($item['gravity'] != GRAVITY_PARENT) || !in_array($item['network'], Protocol::FEDERATED)) {
+		if (($item['uid'] != 0) || ($item['gravity'] != self::GRAVITY_PARENT) || !in_array($item['network'], Protocol::FEDERATED)) {
 			return;
 		}
 
@@ -1542,7 +1548,7 @@ class Item
 			return 0;
 		}
 
-		if (($uid != 0) && ($item['gravity'] == GRAVITY_PARENT)) {
+		if (($uid != 0) && ($item['gravity'] == self::GRAVITY_PARENT)) {
 			$owner = User::getOwnerDataById($uid);
 			if (($owner['contact-type'] == User::ACCOUNT_TYPE_COMMUNITY) && !Tag::isMentioned($uri_id, $owner['url'])) {
 				Logger::info('Target user is a forum but is not mentioned here, thread will not be stored', ['uid' => $uid, 'uri-id' => $uri_id]);
@@ -1559,13 +1565,13 @@ class Item
 
 		$item = array_merge($item, $fields);
 
-		if (($uid != 0) && Contact::isSharing(($item['gravity'] == GRAVITY_PARENT) ? $item['owner-id'] : $item['author-id'], $uid)) {
+		if (($uid != 0) && Contact::isSharing(($item['gravity'] == Item::GRAVITY_PARENT) ? $item['owner-id'] : $item['author-id'], $uid)) {
 			$item['post-reason'] = self::PR_FOLLOWER;
 		}
 
-		$is_reshare = ($item['gravity'] == GRAVITY_ACTIVITY) && ($item['verb'] == Activity::ANNOUNCE);
+		$is_reshare = ($item['gravity'] == self::GRAVITY_ACTIVITY) && ($item['verb'] == Activity::ANNOUNCE);
 
-		if (($uid != 0) && (($item['gravity'] == GRAVITY_PARENT) || $is_reshare) &&
+		if (($uid != 0) && (($item['gravity'] == self::GRAVITY_PARENT) || $is_reshare) &&
 			DI::pConfig()->get($uid, 'system', 'accept_only_sharer') == self::COMPLETION_NONE &&
 			!in_array($item['post-reason'], [self::PR_FOLLOWER, self::PR_TAG, self::PR_TO, self::PR_CC])) {
 			Logger::info('Contact is not a follower, thread will not be stored', ['author' => $item['author-link'], 'uid' => $uid, 'uri-id' => $uri_id, 'post-reason' => $item['post-reason']]);
@@ -1574,7 +1580,7 @@ class Item
 
 		$causer = $item['causer-id'] ?: $item['author-id'];
 
-		if (($uri_id != $item['parent-uri-id']) && ($item['gravity'] == GRAVITY_COMMENT) && !Post::exists(['uri-id' => $item['parent-uri-id'], 'uid' => $uid])) {
+		if (($uri_id != $item['parent-uri-id']) && ($item['gravity'] == self::GRAVITY_COMMENT) && !Post::exists(['uri-id' => $item['parent-uri-id'], 'uid' => $uid])) {
 			if (!self::fetchParent($item['parent-uri-id'], $uid, $causer)) {
 				Logger::info('Parent post had not been added', ['uri-id' => $item['parent-uri-id'], 'uid' => $uid, 'causer' => $causer]);
 				return 0;
@@ -1715,7 +1721,7 @@ class Item
 		$item['contact-id'] = self::contactId($item);
 
 		$notify = false;
-		if ($item['gravity'] == GRAVITY_PARENT) {
+		if ($item['gravity'] == self::GRAVITY_PARENT) {
 			$contact = DBA::selectFirst('contact', [], ['id' => $item['contact-id'], 'self' => false]);
 			if (DBA::isResult($contact)) {
 				$notify = self::isRemoteSelf($contact, $item);
@@ -1745,7 +1751,7 @@ class Item
 	private static function addShadow(int $itemid)
 	{
 		$fields = ['uid', 'private', 'visible', 'deleted', 'network', 'uri-id'];
-		$condition = ['id' => $itemid, 'gravity' => GRAVITY_PARENT];
+		$condition = ['id' => $itemid, 'gravity' => self::GRAVITY_PARENT];
 		$item = Post::selectFirst($fields, $condition);
 
 		if (!DBA::isResult($item)) {
@@ -1813,7 +1819,7 @@ class Item
 		}
 
 		// Is it a toplevel post?
-		if ($item['gravity'] == GRAVITY_PARENT) {
+		if ($item['gravity'] == self::GRAVITY_PARENT) {
 			self::addShadow($itemid);
 			return;
 		}
@@ -1875,7 +1881,7 @@ class Item
 			return $item['language'];
 		}
 
-		if (!in_array($item['gravity'], [GRAVITY_PARENT, GRAVITY_COMMENT]) || empty($item['body'])) {
+		if (!in_array($item['gravity'], [self::GRAVITY_PARENT, self::GRAVITY_COMMENT]) || empty($item['body'])) {
 			return '';
 		}
 
@@ -2155,13 +2161,13 @@ class Item
 			return false;
 		}
 
-		$item = Post::selectFirst(self::ITEM_FIELDLIST, ['id' => $item_id, 'gravity' => [GRAVITY_PARENT, GRAVITY_COMMENT], 'origin' => false]);
+		$item = Post::selectFirst(self::ITEM_FIELDLIST, ['id' => $item_id, 'gravity' => [self::GRAVITY_PARENT, self::GRAVITY_COMMENT], 'origin' => false]);
 		if (!DBA::isResult($item)) {
 			Logger::debug('Post is an activity or origin or not found at all, quitting here.', ['id' => $item_id]);
 			return false;
 		}
 
-		if ($item['gravity'] == GRAVITY_PARENT) {
+		if ($item['gravity'] == self::GRAVITY_PARENT) {
 			if (Tag::isMentioned($item['uri-id'], $owner['url'])) {
 				Logger::info('Mention found in tag.', ['uri' => $item['uri'], 'uid' => $uid, 'id' => $item_id, 'uri-id' => $item['uri-id'], 'guid' => $item['guid']]);
 			} else {
@@ -2206,7 +2212,7 @@ class Item
 	 */
 	private static function autoReshare(array $item)
 	{
-		if ($item['gravity'] != GRAVITY_PARENT) {
+		if ($item['gravity'] != self::GRAVITY_PARENT) {
 			return;
 		}
 
@@ -2467,7 +2473,7 @@ class Item
 		}
 
 		$condition = ["`uid` = ? AND NOT `deleted` AND `gravity` = ?",
-			$uid, GRAVITY_PARENT];
+			$uid, self::GRAVITY_PARENT];
 
 		/*
 		 * $expire_network_only = save your own wall posts
@@ -2674,7 +2680,7 @@ class Item
 			$vids = Verb::getID($activity);
 		}
 
-		$condition = ['vid' => $vids, 'deleted' => false, 'gravity' => GRAVITY_ACTIVITY,
+		$condition = ['vid' => $vids, 'deleted' => false, 'gravity' => self::GRAVITY_ACTIVITY,
 			'author-id' => $author_id, 'uid' => $item['uid'], 'thr-parent-id' => $uri_id];
 		$like_item = Post::selectFirst(['id', 'guid', 'verb'], $condition);
 
@@ -2728,7 +2734,7 @@ class Item
 			'network'       => Protocol::DFRN,
 			'protocol'      => Conversation::PARCEL_DIRECT,
 			'direction'     => Conversation::PUSH,
-			'gravity'       => GRAVITY_ACTIVITY,
+			'gravity'       => self::GRAVITY_ACTIVITY,
 			'parent'        => $item['id'],
 			'thr-parent'    => $item['uri'],
 			'owner-id'      => $author_id,
@@ -2853,9 +2859,9 @@ class Item
 			return $l10n->t('event');
 		} elseif (!empty($item['resource-id'])) {
 			return $l10n->t('photo');
-		} elseif ($item['gravity'] == GRAVITY_ACTIVITY) {
+		} elseif ($item['gravity'] == self::GRAVITY_ACTIVITY) {
 			return $l10n->t('activity');
-		} elseif ($item['gravity'] == GRAVITY_COMMENT) {
+		} elseif ($item['gravity'] == self::GRAVITY_COMMENT) {
 			return $l10n->t('comment');
 		}
 
@@ -3627,7 +3633,7 @@ class Item
 			return false;
 		}
 
-		if (!empty($item['causer-id']) && ($item['gravity'] === GRAVITY_PARENT) && Contact\User::isIgnored($item['causer-id'], $user_id)) {
+		if (!empty($item['causer-id']) && ($item['gravity'] === self::GRAVITY_PARENT) && Contact\User::isIgnored($item['causer-id'], $user_id)) {
 			Logger::notice('Causer is ignored by user', ['causer-link' => $item['causer-link'] ?? $item['causer-id'], 'uid' => $user_id, 'item-uri' => $item['uri']]);
 			return false;
 		}
diff --git a/src/Model/Nodeinfo.php b/src/Model/Nodeinfo.php
index 5ce7f89513..9a4d2bd60f 100644
--- a/src/Model/Nodeinfo.php
+++ b/src/Model/Nodeinfo.php
@@ -25,6 +25,7 @@ use Friendica\Core\Addon;
 use Friendica\Core\Config\Capability\IManageConfigValues;
 use Friendica\Database\DBA;
 use Friendica\DI;
+use Friendica\Model\Item;
 use stdClass;
 
 /**
@@ -62,8 +63,8 @@ class Nodeinfo
 		$logger->info('user statistics', $userStats);
 
 		$posts = DBA::count('post-thread', ["`uri-id` IN (SELECT `uri-id` FROM `post-user` WHERE NOT `deleted` AND `origin`)"]);
-		$comments = DBA::count('post', ["NOT `deleted` AND `gravity` = ? AND `uri-id` IN (SELECT `uri-id` FROM `post-user` WHERE `origin`)", GRAVITY_COMMENT]);
-				$config->set('nodeinfo', 'local_posts', $posts);
+		$comments = DBA::count('post', ["NOT `deleted` AND `gravity` = ? AND `uri-id` IN (SELECT `uri-id` FROM `post-user` WHERE `origin`)", Item::GRAVITY_COMMENT]);
+		$config->set('nodeinfo', 'local_posts', $posts);
 		$config->set('nodeinfo', 'local_comments', $comments);
 
 		$logger->info('User actitivy', ['posts' => $posts, 'comments' => $comments]);
diff --git a/src/Model/Post.php b/src/Model/Post.php
index 4b1d70ae96..e78e0f706f 100644
--- a/src/Model/Post.php
+++ b/src/Model/Post.php
@@ -28,6 +28,7 @@ use Friendica\Database\Database;
 use Friendica\Database\DBA;
 use Friendica\Database\DBStructure;
 use Friendica\DI;
+use Friendica\Model\Item;
 use Friendica\Protocol\Activity;
 
 class Post
@@ -405,7 +406,7 @@ class Post
 			AND NOT `owner-id` IN (SELECT `cid` FROM `user-contact` WHERE `uid` = ? AND `blocked`)
 			AND NOT (`gravity` = ? AND `author-id` IN (SELECT `cid` FROM `user-contact` WHERE `uid` = ? AND `ignored`))
 			AND NOT (`gravity` = ? AND `owner-id` IN (SELECT `cid` FROM `user-contact` WHERE `uid` = ? AND `ignored`))",
-			0, Contact::SHARING, Contact::FRIEND, GRAVITY_PARENT, 0, $uid, $uid, $uid, GRAVITY_PARENT, $uid, GRAVITY_PARENT, $uid]);
+			0, Contact::SHARING, Contact::FRIEND, Item::GRAVITY_PARENT, 0, $uid, $uid, $uid, Item::GRAVITY_PARENT, $uid, Item::GRAVITY_PARENT, $uid]);
 
 		$select_string = implode(', ', array_map([DBA::class, 'quoteIdentifier'], $selected));
 
@@ -520,7 +521,7 @@ class Post
 		unset($fields['parent-uri']);
 		unset($fields['parent-uri-id']);
 
-		$thread_condition = DBA::mergeConditions($condition, ['gravity' => GRAVITY_PARENT]);
+		$thread_condition = DBA::mergeConditions($condition, ['gravity' => Item::GRAVITY_PARENT]);
 
 		// To ensure the data integrity we do it in an transaction
 		DBA::transaction();
diff --git a/src/Model/Post/UserNotification.php b/src/Model/Post/UserNotification.php
index 4a57ff6ff5..108f3c44ff 100644
--- a/src/Model/Post/UserNotification.php
+++ b/src/Model/Post/UserNotification.php
@@ -30,6 +30,7 @@ use Friendica\Database\DBA;
 use Friendica\Database\DBStructure;
 use Friendica\DI;
 use Friendica\Model\Contact;
+use Friendica\Model\Item;
 use Friendica\Model\Post;
 use Friendica\Model\Subscription;
 use Friendica\Model\Tag;
@@ -288,7 +289,7 @@ class UserNotification
 		}
 
 		// Only create notifications for posts and comments, not for activities
-		if (($item['gravity'] == GRAVITY_ACTIVITY) && ($item['verb'] != Activity::ANNOUNCE)) {
+		if (($item['gravity'] == Item::GRAVITY_ACTIVITY) && ($item['verb'] != Activity::ANNOUNCE)) {
 			return;
 		}
 
@@ -310,7 +311,7 @@ class UserNotification
 	 */
 	private static function insertNotificationByItem(int $type, int $uid, array $item): void
 	{
-		if (($item['verb'] != Activity::ANNOUNCE) && ($item['gravity'] == GRAVITY_ACTIVITY) &&
+		if (($item['verb'] != Activity::ANNOUNCE) && ($item['gravity'] == Item::GRAVITY_ACTIVITY) &&
 			!in_array($type, [self::TYPE_DIRECT_COMMENT, self::TYPE_DIRECT_THREAD_COMMENT])) {
 			// Activities are only stored when performed on the user's post or comment
 			return;
@@ -321,7 +322,7 @@ class UserNotification
 			$item['vid'],
 			$type,
 			$item['author-id'],
-			$item['gravity'] == GRAVITY_ACTIVITY ? $item['thr-parent-id'] : $item['uri-id'],
+			$item['gravity'] == Item::GRAVITY_ACTIVITY ? $item['thr-parent-id'] : $item['uri-id'],
 			$item['parent-uri-id']
 		);
 
@@ -423,14 +424,14 @@ class UserNotification
 	private static function checkShared(array $item, int $uid): bool
 	{
 		// Only check on original posts and reshare ("announce") activities, otherwise return
-		if (($item['gravity'] != GRAVITY_PARENT) && ($item['verb'] != Activity::ANNOUNCE)) {
+		if (($item['gravity'] != Item::GRAVITY_PARENT) && ($item['verb'] != Activity::ANNOUNCE)) {
 			return false;
 		}
 
 		// Don't notify about reshares by communities of our own posts or each time someone comments
 		if (($item['verb'] == Activity::ANNOUNCE) && DBA::exists('contact', ['id' => $item['contact-id'], 'contact-type' => Contact::TYPE_COMMUNITY])) {
 			$post = Post::selectFirst(['origin', 'gravity'], ['uri-id' => $item['thr-parent-id'], 'uid' => $uid]);
-			if ($post['origin'] || ($post['gravity'] != GRAVITY_PARENT)) {
+			if ($post['origin'] || ($post['gravity'] != Item::GRAVITY_PARENT)) {
 				return false;
 			}
 		}
@@ -497,7 +498,7 @@ class UserNotification
 	 */
 	private static function checkCommentedThread(array $item, array $contacts): bool
 	{
-		$condition = ['parent' => $item['parent'], 'author-id' => $contacts, 'deleted' => false, 'gravity' => GRAVITY_PARENT];
+		$condition = ['parent' => $item['parent'], 'author-id' => $contacts, 'deleted' => false, 'gravity' => Item::GRAVITY_PARENT];
 		return Post::exists($condition);
 	}
 
@@ -511,7 +512,7 @@ class UserNotification
 	 */
 	private static function checkDirectComment(array $item, array $contacts): bool
 	{
-		$condition = ['uri' => $item['thr-parent'], 'uid' => $item['uid'], 'author-id' => $contacts, 'deleted' => false, 'gravity' => GRAVITY_COMMENT];
+		$condition = ['uri' => $item['thr-parent'], 'uid' => $item['uid'], 'author-id' => $contacts, 'deleted' => false, 'gravity' => Item::GRAVITY_COMMENT];
 		return Post::exists($condition);
 	}
 
@@ -525,7 +526,7 @@ class UserNotification
 	 */
 	private static function checkDirectCommentedThread(array $item, array $contacts): bool
 	{
-		$condition = ['uri' => $item['thr-parent'], 'uid' => $item['uid'], 'author-id' => $contacts, 'deleted' => false, 'gravity' => GRAVITY_PARENT];
+		$condition = ['uri' => $item['thr-parent'], 'uid' => $item['uid'], 'author-id' => $contacts, 'deleted' => false, 'gravity' => Item::GRAVITY_PARENT];
 		return Post::exists($condition);
 	}
 
@@ -539,7 +540,7 @@ class UserNotification
 	 */
 	private static function checkCommentedParticipation(array $item, array $contacts): bool
 	{
-		$condition = ['parent' => $item['parent'], 'author-id' => $contacts, 'deleted' => false, 'gravity' => GRAVITY_COMMENT];
+		$condition = ['parent' => $item['parent'], 'author-id' => $contacts, 'deleted' => false, 'gravity' => Item::GRAVITY_COMMENT];
 		return Post::exists($condition);
 	}
 
@@ -553,7 +554,7 @@ class UserNotification
 	 */
 	private static function checkFollowParticipation(array $item, array $contacts): bool
 	{
-		$condition = ['parent' => $item['parent'], 'author-id' => $contacts, 'deleted' => false, 'gravity' => GRAVITY_ACTIVITY, 'verb' => Activity::FOLLOW];
+		$condition = ['parent' => $item['parent'], 'author-id' => $contacts, 'deleted' => false, 'gravity' => Item::GRAVITY_ACTIVITY, 'verb' => Activity::FOLLOW];
 		return Post::exists($condition);
 	}
 
@@ -567,7 +568,7 @@ class UserNotification
 	 */
 	private static function checkActivityParticipation(array $item, array $contacts): bool
 	{
-		$condition = ['parent' => $item['parent'], 'author-id' => $contacts, 'deleted' => false, 'gravity' => GRAVITY_ACTIVITY];
+		$condition = ['parent' => $item['parent'], 'author-id' => $contacts, 'deleted' => false, 'gravity' => Item::GRAVITY_ACTIVITY];
 		return Post::exists($condition);
 	}
 }
diff --git a/src/Module/ActivityPub/Objects.php b/src/Module/ActivityPub/Objects.php
index 96b3f638e7..e2328b5e58 100644
--- a/src/Module/ActivityPub/Objects.php
+++ b/src/Module/ActivityPub/Objects.php
@@ -97,7 +97,7 @@ class Objects extends BaseModule
 		$last_modified = $item['changed'];
 		Network::checkEtagModified($etag, $last_modified);
 
-		if (empty($this->parameters['activity']) && ($item['gravity'] != GRAVITY_ACTIVITY)) {
+		if (empty($this->parameters['activity']) && ($item['gravity'] != Item::GRAVITY_ACTIVITY)) {
 			$activity = ActivityPub\Transmitter::createCachedActivityFromItem($item['id'], false, true);
 			if (empty($activity['type'])) {
 				throw new HTTPException\NotFoundException();
diff --git a/src/Module/Api/GNUSocial/Statusnet/Conversation.php b/src/Module/Api/GNUSocial/Statusnet/Conversation.php
index 98d1de14d0..fc52e9fed5 100644
--- a/src/Module/Api/GNUSocial/Statusnet/Conversation.php
+++ b/src/Module/Api/GNUSocial/Statusnet/Conversation.php
@@ -26,6 +26,7 @@ use Friendica\Database\DBA;
 use Friendica\Module\BaseApi;
 use Friendica\DI;
 use Friendica\Model\Contact;
+use Friendica\Model\Item;
 use Friendica\Model\Post;
 use Friendica\Network\HTTPException\BadRequestException;
 
@@ -69,7 +70,7 @@ class Conversation extends BaseApi
 		$id = $parent['id'];
 
 		$condition = ["`parent` = ? AND `uid` IN (0, ?) AND `gravity` IN (?, ?) AND `uri-id` > ?",
-			$id, $uid, GRAVITY_PARENT, GRAVITY_COMMENT, $since_id];
+			$id, $uid, Item::GRAVITY_PARENT, Item::GRAVITY_COMMENT, $since_id];
 
 		if ($max_id > 0) {
 			$condition[0] .= " AND `uri-id` <= ?";
diff --git a/src/Module/Api/Mastodon/Accounts/Statuses.php b/src/Module/Api/Mastodon/Accounts/Statuses.php
index 7c75ea5cfc..9481172129 100644
--- a/src/Module/Api/Mastodon/Accounts/Statuses.php
+++ b/src/Module/Api/Mastodon/Accounts/Statuses.php
@@ -78,7 +78,7 @@ class Statuses extends BaseApi
 
 		if (!$request['pinned']) {
 			$condition = DBA::mergeConditions($condition, ["(`gravity` IN (?, ?) OR (`gravity` = ? AND `vid` = ?))",
-				GRAVITY_PARENT, GRAVITY_COMMENT, GRAVITY_ACTIVITY, Verb::getID(Activity::ANNOUNCE)]);
+				Item::GRAVITY_PARENT, Item::GRAVITY_COMMENT, Item::GRAVITY_ACTIVITY, Verb::getID(Activity::ANNOUNCE)]);
 		}
 
 		if ($request['only_media']) {
@@ -100,7 +100,7 @@ class Statuses extends BaseApi
 		}
 
 		if ($request['exclude_replies']) {
-			$condition = DBA::mergeConditions($condition, ['gravity' => GRAVITY_PARENT]);
+			$condition = DBA::mergeConditions($condition, ['gravity' => Item::GRAVITY_PARENT]);
 		}
 
 		if ($request['pinned']) {
diff --git a/src/Module/Api/Mastodon/Favourited.php b/src/Module/Api/Mastodon/Favourited.php
index cd6e2bee12..ca21cc62b6 100644
--- a/src/Module/Api/Mastodon/Favourited.php
+++ b/src/Module/Api/Mastodon/Favourited.php
@@ -24,6 +24,7 @@ namespace Friendica\Module\Api\Mastodon;
 use Friendica\Core\System;
 use Friendica\Database\DBA;
 use Friendica\DI;
+use Friendica\Model\Item;
 use Friendica\Model\Post;
 use Friendica\Module\BaseApi;
 use Friendica\Network\HTTPException;
@@ -51,7 +52,7 @@ class Favourited extends BaseApi
 
 		$params = ['order' => ['thr-parent-id' => true], 'limit' => $request['limit']];
 
-		$condition = ['gravity' => GRAVITY_ACTIVITY, 'origin' => true, 'verb' => Activity::LIKE, 'uid' => $uid];
+		$condition = ['gravity' => Item::GRAVITY_ACTIVITY, 'origin' => true, 'verb' => Activity::LIKE, 'uid' => $uid];
 
 		if (!empty($request['max_id'])) {
 			$condition = DBA::mergeConditions($condition, ["`thr-parent-id` < ?", $request['max_id']]);
diff --git a/src/Module/Api/Mastodon/Statuses.php b/src/Module/Api/Mastodon/Statuses.php
index 8cc3e3ddf2..7fe369d00e 100644
--- a/src/Module/Api/Mastodon/Statuses.php
+++ b/src/Module/Api/Mastodon/Statuses.php
@@ -152,13 +152,13 @@ class Statuses extends BaseApi
 			$parent = Post::selectFirst(['uri'], ['uri-id' => $request['in_reply_to_id'], 'uid' => [0, $uid]]);
 
 			$item['thr-parent']  = $parent['uri'];
-			$item['gravity']     = GRAVITY_COMMENT;
+			$item['gravity']     = Item::GRAVITY_COMMENT;
 			$item['object-type'] = Activity\ObjectType::COMMENT;
 			$item['body']        = '[abstract=' . Protocol::ACTIVITYPUB . ']' . $request['spoiler_text'] . "[/abstract]\n" . $item['body'];
 		} else {
 			self::checkThrottleLimit();
 
-			$item['gravity']     = GRAVITY_PARENT;
+			$item['gravity']     = Item::GRAVITY_PARENT;
 			$item['object-type'] = Activity\ObjectType::NOTE;
 			$item['title']       = $request['spoiler_text'];
 		}
diff --git a/src/Module/Api/Mastodon/Statuses/Bookmark.php b/src/Module/Api/Mastodon/Statuses/Bookmark.php
index cebb061927..8c9a21a784 100644
--- a/src/Module/Api/Mastodon/Statuses/Bookmark.php
+++ b/src/Module/Api/Mastodon/Statuses/Bookmark.php
@@ -47,7 +47,7 @@ class Bookmark extends BaseApi
 			DI::mstdnError()->RecordNotFound();
 		}
 
-		if ($item['gravity'] != GRAVITY_PARENT) {
+		if ($item['gravity'] != Item::GRAVITY_PARENT) {
 			DI::mstdnError()->UnprocessableEntity(DI::l10n()->t('Only starting posts can be bookmarked'));
 		}
 
diff --git a/src/Module/Api/Mastodon/Statuses/Context.php b/src/Module/Api/Mastodon/Statuses/Context.php
index a15b3c4649..08ec094e00 100644
--- a/src/Module/Api/Mastodon/Statuses/Context.php
+++ b/src/Module/Api/Mastodon/Statuses/Context.php
@@ -24,6 +24,7 @@ namespace Friendica\Module\Api\Mastodon\Statuses;
 use Friendica\Core\System;
 use Friendica\Database\DBA;
 use Friendica\DI;
+use Friendica\Model\Item;
 use Friendica\Model\Post;
 use Friendica\Module\BaseApi;
 
@@ -55,7 +56,7 @@ class Context extends BaseApi
 		$parent = Post::selectFirst(['parent-uri-id'], ['uri-id' => $id]);
 		if (DBA::isResult($parent)) {
 			$posts = Post::selectPosts(['uri-id', 'thr-parent-id'],
-				['parent-uri-id' => $parent['parent-uri-id'], 'gravity' => [GRAVITY_PARENT, GRAVITY_COMMENT]]);
+				['parent-uri-id' => $parent['parent-uri-id'], 'gravity' => [Item::GRAVITY_PARENT, Item::GRAVITY_COMMENT]]);
 			while ($post = Post::fetch($posts)) {
 				if ($post['uri-id'] == $post['thr-parent-id']) {
 					continue;
diff --git a/src/Module/Api/Mastodon/Statuses/FavouritedBy.php b/src/Module/Api/Mastodon/Statuses/FavouritedBy.php
index ebf8b63367..30e6ad152e 100644
--- a/src/Module/Api/Mastodon/Statuses/FavouritedBy.php
+++ b/src/Module/Api/Mastodon/Statuses/FavouritedBy.php
@@ -23,6 +23,7 @@ namespace Friendica\Module\Api\Mastodon\Statuses;
 
 use Friendica\Core\System;
 use Friendica\DI;
+use Friendica\Model\Item;
 use Friendica\Model\Post;
 use Friendica\Module\BaseApi;
 use Friendica\Protocol\Activity;
@@ -48,7 +49,7 @@ class FavouritedBy extends BaseApi
 			DI::mstdnError()->RecordNotFound();
 		}
 
-		$activities = Post::selectPosts(['author-id'], ['thr-parent-id' => $id, 'gravity' => GRAVITY_ACTIVITY, 'verb' => Activity::LIKE]);
+		$activities = Post::selectPosts(['author-id'], ['thr-parent-id' => $id, 'gravity' => Item::GRAVITY_ACTIVITY, 'verb' => Activity::LIKE]);
 
 		$accounts = [];
 
diff --git a/src/Module/Api/Mastodon/Statuses/Mute.php b/src/Module/Api/Mastodon/Statuses/Mute.php
index e98af8ad75..152a249f1e 100644
--- a/src/Module/Api/Mastodon/Statuses/Mute.php
+++ b/src/Module/Api/Mastodon/Statuses/Mute.php
@@ -24,6 +24,7 @@ namespace Friendica\Module\Api\Mastodon\Statuses;
 use Friendica\Core\System;
 use Friendica\Database\DBA;
 use Friendica\DI;
+use Friendica\Model\Item;
 use Friendica\Model\Post;
 use Friendica\Module\BaseApi;
 
@@ -46,7 +47,7 @@ class Mute extends BaseApi
 			DI::mstdnError()->RecordNotFound();
 		}
 
-		if ($item['gravity'] != GRAVITY_PARENT) {
+		if ($item['gravity'] != Item::GRAVITY_PARENT) {
 			DI::mstdnError()->UnprocessableEntity(DI::l10n()->t('Only starting posts can be muted'));
 		}
 
diff --git a/src/Module/Api/Mastodon/Statuses/RebloggedBy.php b/src/Module/Api/Mastodon/Statuses/RebloggedBy.php
index 10fd65a02f..39a93de0c0 100644
--- a/src/Module/Api/Mastodon/Statuses/RebloggedBy.php
+++ b/src/Module/Api/Mastodon/Statuses/RebloggedBy.php
@@ -23,6 +23,7 @@ namespace Friendica\Module\Api\Mastodon\Statuses;
 
 use Friendica\Core\System;
 use Friendica\DI;
+use Friendica\Model\Item;
 use Friendica\Model\Post;
 use Friendica\Module\BaseApi;
 use Friendica\Protocol\Activity;
@@ -48,7 +49,7 @@ class RebloggedBy extends BaseApi
 			DI::mstdnError()->RecordNotFound();
 		}
 
-		$activities = Post::selectPosts(['author-id'], ['thr-parent-id' => $id, 'gravity' => GRAVITY_ACTIVITY, 'verb' => Activity::ANNOUNCE]);
+		$activities = Post::selectPosts(['author-id'], ['thr-parent-id' => $id, 'gravity' => Item::GRAVITY_ACTIVITY, 'verb' => Activity::ANNOUNCE]);
 
 		$accounts = [];
 
diff --git a/src/Module/Api/Mastodon/Statuses/Unbookmark.php b/src/Module/Api/Mastodon/Statuses/Unbookmark.php
index f90916176d..d7e06c32d9 100644
--- a/src/Module/Api/Mastodon/Statuses/Unbookmark.php
+++ b/src/Module/Api/Mastodon/Statuses/Unbookmark.php
@@ -47,7 +47,7 @@ class Unbookmark extends BaseApi
 			DI::mstdnError()->RecordNotFound();
 		}
 
-		if ($item['gravity'] != GRAVITY_PARENT) {
+		if ($item['gravity'] != Item::GRAVITY_PARENT) {
 			DI::mstdnError()->UnprocessableEntity(DI::l10n()->t('Only starting posts can be unbookmarked'));
 		}
 
diff --git a/src/Module/Api/Mastodon/Statuses/Unmute.php b/src/Module/Api/Mastodon/Statuses/Unmute.php
index 722d70f8df..5cf4ceedb5 100644
--- a/src/Module/Api/Mastodon/Statuses/Unmute.php
+++ b/src/Module/Api/Mastodon/Statuses/Unmute.php
@@ -24,6 +24,7 @@ namespace Friendica\Module\Api\Mastodon\Statuses;
 use Friendica\Core\System;
 use Friendica\Database\DBA;
 use Friendica\DI;
+use Friendica\Model\Item;
 use Friendica\Model\Post;
 use Friendica\Module\BaseApi;
 
@@ -46,7 +47,7 @@ class Unmute extends BaseApi
 			DI::mstdnError()->RecordNotFound();
 		}
 
-		if ($item['gravity'] != GRAVITY_PARENT) {
+		if ($item['gravity'] != Item::GRAVITY_PARENT) {
 			DI::mstdnError()->UnprocessableEntity(DI::l10n()->t('Only starting posts can be unmuted'));
 		}
 
diff --git a/src/Module/Api/Mastodon/Timelines/Home.php b/src/Module/Api/Mastodon/Timelines/Home.php
index 494351db2d..3a18baecbf 100644
--- a/src/Module/Api/Mastodon/Timelines/Home.php
+++ b/src/Module/Api/Mastodon/Timelines/Home.php
@@ -24,6 +24,7 @@ namespace Friendica\Module\Api\Mastodon\Timelines;
 use Friendica\Core\System;
 use Friendica\Database\DBA;
 use Friendica\DI;
+use Friendica\Model\Item;
 use Friendica\Model\Post;
 use Friendica\Module\BaseApi;
 use Friendica\Network\HTTPException;
@@ -55,7 +56,7 @@ class Home extends BaseApi
 
 		$params = ['order' => ['uri-id' => true], 'limit' => $request['limit']];
 
-		$condition = ['gravity' => [GRAVITY_PARENT, GRAVITY_COMMENT], 'uid' => $uid];
+		$condition = ['gravity' => [Item::GRAVITY_PARENT, Item::GRAVITY_COMMENT], 'uid' => $uid];
 
 		if ($request['local']) {
 			$condition = DBA::mergeConditions($condition, ["`uri-id` IN (SELECT `uri-id` FROM `post-user` WHERE `origin`)"]);
@@ -85,7 +86,7 @@ class Home extends BaseApi
 		}
 
 		if ($request['exclude_replies']) {
-			$condition = DBA::mergeConditions($condition, ['gravity' => GRAVITY_PARENT]);
+			$condition = DBA::mergeConditions($condition, ['gravity' => Item::GRAVITY_PARENT]);
 		}
 
 		$items = Post::selectForUser($uid, ['uri-id'], $condition, $params);
diff --git a/src/Module/Api/Mastodon/Timelines/ListTimeline.php b/src/Module/Api/Mastodon/Timelines/ListTimeline.php
index 011f66ac16..c786e3d9dc 100644
--- a/src/Module/Api/Mastodon/Timelines/ListTimeline.php
+++ b/src/Module/Api/Mastodon/Timelines/ListTimeline.php
@@ -24,6 +24,7 @@ namespace Friendica\Module\Api\Mastodon\Timelines;
 use Friendica\Core\System;
 use Friendica\Database\DBA;
 use Friendica\DI;
+use Friendica\Model\Item;
 use Friendica\Model\Post;
 use Friendica\Module\BaseApi;
 use Friendica\Network\HTTPException;
@@ -60,7 +61,7 @@ class ListTimeline extends BaseApi
 		$params = ['order' => ['uri-id' => true], 'limit' => $request['limit']];
 
 		$condition = ["`uid` = ? AND `gravity` IN (?, ?) AND `contact-id` IN (SELECT `contact-id` FROM `group_member` WHERE `gid` = ?)",
-			$uid, GRAVITY_PARENT, GRAVITY_COMMENT, $this->parameters['id']];
+			$uid, Item::GRAVITY_PARENT, Item::GRAVITY_COMMENT, $this->parameters['id']];
 
 		if (!empty($request['max_id'])) {
 			$condition = DBA::mergeConditions($condition, ["`uri-id` < ?", $request['max_id']]);
@@ -82,7 +83,7 @@ class ListTimeline extends BaseApi
 		}
 
 		if ($request['exclude_replies']) {
-			$condition = DBA::mergeConditions($condition, ['gravity' => GRAVITY_PARENT]);
+			$condition = DBA::mergeConditions($condition, ['gravity' => Item::GRAVITY_PARENT]);
 		}
 
 		if ($request['local']) {
diff --git a/src/Module/Api/Mastodon/Timelines/PublicTimeline.php b/src/Module/Api/Mastodon/Timelines/PublicTimeline.php
index d34deac079..cc2392caff 100644
--- a/src/Module/Api/Mastodon/Timelines/PublicTimeline.php
+++ b/src/Module/Api/Mastodon/Timelines/PublicTimeline.php
@@ -57,7 +57,7 @@ class PublicTimeline extends BaseApi
 
 		$params = ['order' => ['uri-id' => true], 'limit' => $request['limit']];
 
-		$condition = ['gravity' => [GRAVITY_PARENT, GRAVITY_COMMENT], 'private' => Item::PUBLIC,
+		$condition = ['gravity' => [Item::GRAVITY_PARENT, Item::GRAVITY_COMMENT], 'private' => Item::PUBLIC,
 			'network' => Protocol::FEDERATED, 'parent-author-blocked' => false, 'parent-author-hidden' => false];
 
 		if ($request['local']) {
@@ -87,7 +87,7 @@ class PublicTimeline extends BaseApi
 		}
 
 		if ($request['exclude_replies']) {
-			$condition = DBA::mergeConditions($condition, ['gravity' => GRAVITY_PARENT]);
+			$condition = DBA::mergeConditions($condition, ['gravity' => Item::GRAVITY_PARENT]);
 		}
 
 		if (!empty($uid)) {
diff --git a/src/Module/Api/Mastodon/Timelines/Tag.php b/src/Module/Api/Mastodon/Timelines/Tag.php
index 541afa1601..bc4464b566 100644
--- a/src/Module/Api/Mastodon/Timelines/Tag.php
+++ b/src/Module/Api/Mastodon/Timelines/Tag.php
@@ -25,6 +25,7 @@ use Friendica\Core\Protocol;
 use Friendica\Core\System;
 use Friendica\Database\DBA;
 use Friendica\DI;
+use Friendica\Model\Item;
 use Friendica\Model\Post;
 use Friendica\Module\BaseApi;
 use Friendica\Network\HTTPException;
@@ -85,7 +86,7 @@ class Tag extends BaseApi
 		}
 
 		if ($request['exclude_replies']) {
-			$condition = DBA::mergeConditions($condition, ['gravity' => GRAVITY_PARENT]);
+			$condition = DBA::mergeConditions($condition, ['gravity' => Item::GRAVITY_PARENT]);
 		}
 
 		if (!empty($request['max_id'])) {
diff --git a/src/Module/Api/Twitter/Favorites.php b/src/Module/Api/Twitter/Favorites.php
index ea7ca42d5c..1e5dbed5b0 100644
--- a/src/Module/Api/Twitter/Favorites.php
+++ b/src/Module/Api/Twitter/Favorites.php
@@ -23,6 +23,7 @@ namespace Friendica\Module\Api\Twitter;
 
 use Friendica\Core\Logger;
 use Friendica\Database\DBA;
+use Friendica\Model\Item;
 use Friendica\Module\BaseApi;
 use Friendica\DI;
 use Friendica\Model\Contact;
@@ -54,7 +55,7 @@ class Favorites extends BaseApi
 		$start = max(0, ($page - 1) * $count);
 
 		$condition = ["`uid` = ? AND `gravity` IN (?, ?) AND `uri-id` > ? AND `starred`",
-			$uid, GRAVITY_PARENT, GRAVITY_COMMENT, $since_id];
+			$uid, Item::GRAVITY_PARENT, Item::GRAVITY_COMMENT, $since_id];
 
 		$params = ['order' => ['uri-id' => true], 'limit' => [$start, $count]];
 
diff --git a/src/Module/Api/Twitter/Lists/Statuses.php b/src/Module/Api/Twitter/Lists/Statuses.php
index 177c5fd0ba..42fd11c364 100644
--- a/src/Module/Api/Twitter/Lists/Statuses.php
+++ b/src/Module/Api/Twitter/Lists/Statuses.php
@@ -26,10 +26,11 @@ use Friendica\Core\L10n;
 use Friendica\Database\Database;
 use Friendica\Database\DBA;
 use Friendica\Factory\Api\Twitter\Status as TwitterStatus;
-use Friendica\Module\BaseApi;
 use Friendica\Model\Contact;
+use Friendica\Model\Item;
 use Friendica\Model\Post;
 use Friendica\Module\Api\ApiResponse;
+use Friendica\Module\BaseApi;
 use Friendica\Network\HTTPException;
 use Friendica\Util\Profiler;
 use Psr\Log\LoggerInterface;
@@ -77,7 +78,7 @@ class Statuses extends BaseApi
 
 		$groups    = $this->dba->selectToArray('group_member', ['contact-id'], ['gid' => $request['list_id']]);
 		$gids      = array_column($groups, 'contact-id');
-		$condition = ['uid' => $uid, 'gravity' => [GRAVITY_PARENT, GRAVITY_COMMENT], 'contact-id' => $gids];
+		$condition = ['uid' => $uid, 'gravity' => [Item::GRAVITY_PARENT, Item::GRAVITY_COMMENT], 'contact-id' => $gids];
 		$condition = DBA::mergeConditions($condition, ["`uri-id` > ?", $since_id]);
 
 		if ($max_id > 0) {
@@ -86,7 +87,7 @@ class Statuses extends BaseApi
 		}
 		if ($exclude_replies) {
 			$condition[0] .= ' AND `gravity` = ?';
-			$condition[] = GRAVITY_PARENT;
+			$condition[] = Item::GRAVITY_PARENT;
 		}
 		if ($conversation_id > 0) {
 			$condition[0] .= " AND `parent-uri-id` = ?";
diff --git a/src/Module/Api/Twitter/Search/Tweets.php b/src/Module/Api/Twitter/Search/Tweets.php
index db25c4eb96..68876c3207 100644
--- a/src/Module/Api/Twitter/Search/Tweets.php
+++ b/src/Module/Api/Twitter/Search/Tweets.php
@@ -78,13 +78,13 @@ class Tweets extends BaseApi
 
 			$condition = ['uri-id' => $uriids];
 			if ($exclude_replies) {
-				$condition['gravity'] = GRAVITY_PARENT;
+				$condition['gravity'] = Item::GRAVITY_PARENT;
 			}
 
 			$params['group_by'] = ['uri-id'];
 		} else {
 			$condition = ["`uri-id` > ?
-				" . ($exclude_replies ? " AND `gravity` = " . GRAVITY_PARENT : ' ') . "
+				" . ($exclude_replies ? " AND `gravity` = " . Item::GRAVITY_PARENT : ' ') . "
 				AND (`uid` = 0 OR (`uid` = ? AND NOT `global`))
 				AND `body` LIKE CONCAT('%',?,'%')",
 				$since_id, $uid, $_REQUEST['q']];
diff --git a/src/Module/Api/Twitter/Statuses/HomeTimeline.php b/src/Module/Api/Twitter/Statuses/HomeTimeline.php
index a607d4c950..30fecd4c71 100644
--- a/src/Module/Api/Twitter/Statuses/HomeTimeline.php
+++ b/src/Module/Api/Twitter/Statuses/HomeTimeline.php
@@ -54,7 +54,7 @@ class HomeTimeline extends BaseApi
 		$start = max(0, ($page - 1) * $count);
 
 		$condition = ["`uid` = ? AND `gravity` IN (?, ?) AND `uri-id` > ?",
-			$uid, GRAVITY_PARENT, GRAVITY_COMMENT, $since_id];
+			$uid, Item::GRAVITY_PARENT, Item::GRAVITY_COMMENT, $since_id];
 
 		if ($max_id > 0) {
 			$condition[0] .= " AND `uri-id` <= ?";
@@ -62,7 +62,7 @@ class HomeTimeline extends BaseApi
 		}
 		if ($exclude_replies) {
 			$condition[0] .= ' AND `gravity` = ?';
-			$condition[] = GRAVITY_PARENT;
+			$condition[] = Item::GRAVITY_PARENT;
 		}
 		if ($conversation_id > 0) {
 			$condition[0] .= " AND `parent-uri-id` = ?";
diff --git a/src/Module/Api/Twitter/Statuses/Mentions.php b/src/Module/Api/Twitter/Statuses/Mentions.php
index 800a91110b..69aeedba67 100644
--- a/src/Module/Api/Twitter/Statuses/Mentions.php
+++ b/src/Module/Api/Twitter/Statuses/Mentions.php
@@ -24,6 +24,7 @@ namespace Friendica\Module\Api\Twitter\Statuses;
 use Friendica\Database\DBA;
 use Friendica\Module\BaseApi;
 use Friendica\DI;
+use Friendica\Model\Item;
 use Friendica\Model\Contact;
 use Friendica\Model\Post;
 
@@ -55,7 +56,7 @@ class Mentions extends BaseApi
 			AND (`uid` = 0 OR (`uid` = ? AND NOT `global`)) AND `uri-id` > ?";
 
 		$condition = [
-			GRAVITY_PARENT, GRAVITY_COMMENT,
+			Item::GRAVITY_PARENT, Item::GRAVITY_COMMENT,
 			$uid,
 			Post\UserNotification::TYPE_EXPLICIT_TAGGED | Post\UserNotification::TYPE_IMPLICIT_TAGGED |
 			Post\UserNotification::TYPE_THREAD_COMMENT | Post\UserNotification::TYPE_DIRECT_COMMENT |
diff --git a/src/Module/Api/Twitter/Statuses/NetworkPublicTimeline.php b/src/Module/Api/Twitter/Statuses/NetworkPublicTimeline.php
index 96469fb437..ab4de33d41 100644
--- a/src/Module/Api/Twitter/Statuses/NetworkPublicTimeline.php
+++ b/src/Module/Api/Twitter/Statuses/NetworkPublicTimeline.php
@@ -47,7 +47,7 @@ class NetworkPublicTimeline extends BaseApi
 		$start = max(0, ($page - 1) * $count);
 
 		$condition = ["`uid` = 0 AND `gravity` IN (?, ?) AND `uri-id` > ? AND `private` = ?",
-			GRAVITY_PARENT, GRAVITY_COMMENT, $since_id, Item::PUBLIC];
+			Item::GRAVITY_PARENT, Item::GRAVITY_COMMENT, $since_id, Item::PUBLIC];
 
 		if ($max_id > 0) {
 			$condition[0] .= " AND `uri-id` <= ?";
diff --git a/src/Module/Api/Twitter/Statuses/PublicTimeline.php b/src/Module/Api/Twitter/Statuses/PublicTimeline.php
index a247e6688f..e38bfa66af 100644
--- a/src/Module/Api/Twitter/Statuses/PublicTimeline.php
+++ b/src/Module/Api/Twitter/Statuses/PublicTimeline.php
@@ -53,7 +53,7 @@ class PublicTimeline extends BaseApi
 
 		if ($exclude_replies && !$conversation_id) {
 			$condition = ["`gravity` = ? AND `uri-id` > ? AND `private` = ? AND `wall` AND NOT `author-hidden`",
-				GRAVITY_PARENT, $since_id, Item::PUBLIC];
+				Item::GRAVITY_PARENT, $since_id, Item::PUBLIC];
 
 			if ($max_id > 0) {
 				$condition[0] .= " AND `uri-id` <= ?";
@@ -64,7 +64,7 @@ class PublicTimeline extends BaseApi
 			$statuses = Post::selectForUser($uid, [], $condition, $params);
 		} else {
 			$condition = ["`gravity` IN (?, ?) AND `uri-id` > ? AND `private` = ? AND `wall` AND `origin` AND NOT `author-hidden`",
-				GRAVITY_PARENT, GRAVITY_COMMENT, $since_id, Item::PUBLIC];
+				Item::GRAVITY_PARENT, Item::GRAVITY_COMMENT, $since_id, Item::PUBLIC];
 
 			if ($max_id > 0) {
 				$condition[0] .= " AND `uri-id` <= ?";
diff --git a/src/Module/Api/Twitter/Statuses/Show.php b/src/Module/Api/Twitter/Statuses/Show.php
index 16bf462678..7f5340c5bb 100644
--- a/src/Module/Api/Twitter/Statuses/Show.php
+++ b/src/Module/Api/Twitter/Statuses/Show.php
@@ -26,6 +26,7 @@ use Friendica\Database\DBA;
 use Friendica\Module\BaseApi;
 use Friendica\DI;
 use Friendica\Model\Contact;
+use Friendica\Model\Item;
 use Friendica\Model\Post;
 use Friendica\Network\HTTPException\BadRequestException;
 
@@ -60,10 +61,10 @@ class Show extends BaseApi
 		$item_id = $item['id'];
 
 		if ($conversation) {
-			$condition = ['parent' => $item_id, 'gravity' => [GRAVITY_PARENT, GRAVITY_COMMENT]];
+			$condition = ['parent' => $item_id, 'gravity' => [Item::GRAVITY_PARENT, Item::GRAVITY_COMMENT]];
 			$params    = ['order' => ['uri-id' => true]];
 		} else {
-			$condition = ['id' => $item_id, 'gravity' => [GRAVITY_PARENT, GRAVITY_COMMENT]];
+			$condition = ['id' => $item_id, 'gravity' => [Item::GRAVITY_PARENT, Item::GRAVITY_COMMENT]];
 			$params    = [];
 		}
 
diff --git a/src/Module/Api/Twitter/Statuses/Update.php b/src/Module/Api/Twitter/Statuses/Update.php
index 0041c03a70..d071675e86 100644
--- a/src/Module/Api/Twitter/Statuses/Update.php
+++ b/src/Module/Api/Twitter/Statuses/Update.php
@@ -113,12 +113,12 @@ class Update extends BaseApi
 			$parent = Post::selectFirst(['uri'], ['uri-id' => $request['in_reply_to_status_id'], 'uid' => [0, $uid]]);
 
 			$item['thr-parent']  = $parent['uri'];
-			$item['gravity']     = GRAVITY_COMMENT;
+			$item['gravity']     = Item::GRAVITY_COMMENT;
 			$item['object-type'] = Activity\ObjectType::COMMENT;
 		} else {
 			self::checkThrottleLimit();
 
-			$item['gravity']     = GRAVITY_PARENT;
+			$item['gravity']     = Item::GRAVITY_PARENT;
 			$item['object-type'] = Activity\ObjectType::NOTE;
 		}
 
diff --git a/src/Module/Api/Twitter/Statuses/UserTimeline.php b/src/Module/Api/Twitter/Statuses/UserTimeline.php
index a6616636ca..088f10600e 100644
--- a/src/Module/Api/Twitter/Statuses/UserTimeline.php
+++ b/src/Module/Api/Twitter/Statuses/UserTimeline.php
@@ -23,10 +23,11 @@ namespace Friendica\Module\Api\Twitter\Statuses;
 
 use Friendica\Core\Logger;
 use Friendica\Database\DBA;
-use Friendica\Module\BaseApi;
 use Friendica\DI;
 use Friendica\Model\Contact;
+use Friendica\Model\Item;
 use Friendica\Model\Post;
+use Friendica\Module\BaseApi;
 
 /**
  * Returns the most recent statuses posted by the user.
@@ -54,11 +55,11 @@ class UserTimeline extends BaseApi
 		$start = max(0, ($page - 1) * $count);
 
 		$condition = ["(`uid` = ? OR (`uid` = ? AND NOT `global`)) AND `gravity` IN (?, ?) AND `uri-id` > ? AND `author-id` = ?",
-			0, $uid, GRAVITY_PARENT, GRAVITY_COMMENT, $since_id, $cid];
+			0, $uid, Item::GRAVITY_PARENT, Item::GRAVITY_COMMENT, $since_id, $cid];
 
 		if ($exclude_replies) {
 			$condition[0] .= ' AND `gravity` = ?';
-			$condition[] = GRAVITY_PARENT;
+			$condition[] = Item::GRAVITY_PARENT;
 		}
 
 		if ($conversation_id > 0) {
diff --git a/src/Module/BaseApi.php b/src/Module/BaseApi.php
index 1ed0b9033a..47557928a9 100644
--- a/src/Module/BaseApi.php
+++ b/src/Module/BaseApi.php
@@ -29,6 +29,7 @@ use Friendica\Core\Logger;
 use Friendica\Core\System;
 use Friendica\DI;
 use Friendica\Model\Contact;
+use Friendica\Model\Item;
 use Friendica\Model\Post;
 use Friendica\Model\User;
 use Friendica\Module\Api\ApiResponse;
@@ -233,7 +234,7 @@ class BaseApi extends BaseModule
 		if ($throttle_day > 0) {
 			$datefrom = date(DateTimeFormat::MYSQL, time() - 24*60*60);
 
-			$condition = ["`gravity` = ? AND `uid` = ? AND `wall` AND `received` > ?", GRAVITY_PARENT, $uid, $datefrom];
+			$condition = ["`gravity` = ? AND `uid` = ? AND `wall` AND `received` > ?", Item::GRAVITY_PARENT, $uid, $datefrom];
 			$posts_day = Post::countThread($condition);
 
 			if ($posts_day > $throttle_day) {
@@ -249,7 +250,7 @@ class BaseApi extends BaseModule
 		if ($throttle_week > 0) {
 			$datefrom = date(DateTimeFormat::MYSQL, time() - 24*60*60*7);
 
-			$condition = ["`gravity` = ? AND `uid` = ? AND `wall` AND `received` > ?", GRAVITY_PARENT, $uid, $datefrom];
+			$condition = ["`gravity` = ? AND `uid` = ? AND `wall` AND `received` > ?", Item::GRAVITY_PARENT, $uid, $datefrom];
 			$posts_week = Post::countThread($condition);
 
 			if ($posts_week > $throttle_week) {
@@ -265,7 +266,7 @@ class BaseApi extends BaseModule
 		if ($throttle_month > 0) {
 			$datefrom = date(DateTimeFormat::MYSQL, time() - 24*60*60*30);
 
-			$condition = ["`gravity` = ? AND `uid` = ? AND `wall` AND `received` > ?", GRAVITY_PARENT, $uid, $datefrom];
+			$condition = ["`gravity` = ? AND `uid` = ? AND `wall` AND `received` > ?", Item::GRAVITY_PARENT, $uid, $datefrom];
 			$posts_month = Post::countThread($condition);
 
 			if ($posts_month > $throttle_month) {
diff --git a/src/Module/Conversation/Network.php b/src/Module/Conversation/Network.php
index cc6146a893..bfdeb7e578 100644
--- a/src/Module/Conversation/Network.php
+++ b/src/Module/Conversation/Network.php
@@ -414,7 +414,7 @@ class Network extends BaseModule
 		} elseif (self::$forumContactId) {
 			$conditionStrings = DBA::mergeConditions($conditionStrings, 
 				["((`contact-id` = ?) OR `uri-id` IN (SELECT `parent-uri-id` FROM `post-user-view` WHERE (`contact-id` = ? AND `gravity` = ? AND `vid` = ? AND `uid` = ?)))",
-				self::$forumContactId, self::$forumContactId, GRAVITY_ACTIVITY, Verb::getID(Activity::ANNOUNCE), local_user()]);
+				self::$forumContactId, self::$forumContactId, Item::GRAVITY_ACTIVITY, Verb::getID(Activity::ANNOUNCE), local_user()]);
 		}
 
 		// Currently only the order modes "received" and "commented" are in use
diff --git a/src/Module/Diaspora/Fetch.php b/src/Module/Diaspora/Fetch.php
index bcb6ba0cae..fb8b7a65ee 100644
--- a/src/Module/Diaspora/Fetch.php
+++ b/src/Module/Diaspora/Fetch.php
@@ -49,7 +49,7 @@ class Fetch extends BaseModule
 
 		// Fetch the item
 		$condition = ['origin' => true, 'private' => [Item::PUBLIC, Item::UNLISTED], 'guid' => $guid,
-			'gravity' => [GRAVITY_PARENT, GRAVITY_COMMENT], 'network' => [Protocol::DFRN, Protocol::DIASPORA]];
+			'gravity' => [Item::GRAVITY_PARENT, Item::GRAVITY_COMMENT], 'network' => [Protocol::DFRN, Protocol::DIASPORA]];
 		$item = Post::selectFirst([], $condition);
 		if (empty($item)) {
 			$condition = ['guid' => $guid, 'network' => [Protocol::DFRN, Protocol::DIASPORA]];
@@ -76,7 +76,7 @@ class Fetch extends BaseModule
 			throw new HTTPException\NotFoundException();
 		}
 
-		if ($item['gravity'] == GRAVITY_PARENT) {
+		if ($item['gravity'] == Item::GRAVITY_PARENT) {
 			$status = Diaspora::buildStatus($item, $user);
 		} else {
 			$status = ['type' => 'comment', 'message' => Diaspora::createCommentSignature($item)];
diff --git a/src/Module/Item/Ignore.php b/src/Module/Item/Ignore.php
index 626d6bb508..4ccc559eb3 100644
--- a/src/Module/Item/Ignore.php
+++ b/src/Module/Item/Ignore.php
@@ -25,6 +25,7 @@ use Friendica\BaseModule;
 use Friendica\Core\Session;
 use Friendica\Core\System;
 use Friendica\DI;
+use Friendica\Model\Item;
 use Friendica\Model\Post;
 use Friendica\Network\HTTPException;
 
@@ -49,7 +50,7 @@ class Ignore extends BaseModule
 
 		$dba = DI::dba();
 
-		$thread = Post::selectFirst(['uri-id', 'uid'], ['id' => $itemId, 'gravity' => GRAVITY_PARENT]);
+		$thread = Post::selectFirst(['uri-id', 'uid'], ['id' => $itemId, 'gravity' => Item::GRAVITY_PARENT]);
 		if (!$dba->isResult($thread)) {
 			throw new HTTPException\NotFoundException();
 		}
diff --git a/src/Module/Profile/Status.php b/src/Module/Profile/Status.php
index 99f5fe6bae..7cdd907c8a 100644
--- a/src/Module/Profile/Status.php
+++ b/src/Module/Profile/Status.php
@@ -176,7 +176,7 @@ class Status extends BaseProfile
 		$condition = DBA::mergeConditions($condition, ["((`gravity` = ? AND `wall`) OR
 			(`gravity` = ? AND `vid` = ? AND `origin`
 			AND `thr-parent-id` IN (SELECT `uri-id` FROM `post` WHERE `gravity` = ? AND `network` = ?)))",
-			GRAVITY_PARENT, GRAVITY_ACTIVITY, Verb::getID(Activity::ANNOUNCE), GRAVITY_PARENT, Protocol::ACTIVITYPUB]);
+			GRAVITY_PARENT, Item::GRAVITY_ACTIVITY, Verb::getID(Activity::ANNOUNCE), Item::GRAVITY_PARENT, Protocol::ACTIVITYPUB]);
 
 		$condition = DBA::mergeConditions($condition, ['uid' => $profile['uid'], 'network' => Protocol::FEDERATED,
 			'visible' => true, 'deleted' => false]);
diff --git a/src/Module/Update/Network.php b/src/Module/Update/Network.php
index 6282028e69..6d452b70c0 100644
--- a/src/Module/Update/Network.php
+++ b/src/Module/Update/Network.php
@@ -23,6 +23,7 @@ namespace Friendica\Module\Update;
 
 use Friendica\Core\System;
 use Friendica\DI;
+use Friendica\Model\Item;
 use Friendica\Model\Post;
 use Friendica\Module\Conversation\Network as NetworkModule;
 
@@ -55,7 +56,7 @@ class Network extends NetworkModule
 			} elseif (self::$order === 'received') {
 				// Only load new toplevel posts
 				$conditionFields['unseen'] = true;
-				$conditionFields['gravity'] = GRAVITY_PARENT;
+				$conditionFields['gravity'] = Item::GRAVITY_PARENT;
 			} else {
 				// Load all unseen items
 				$conditionFields['unseen'] = true;
diff --git a/src/Module/Update/Profile.php b/src/Module/Update/Profile.php
index 50d0eddd14..b7dae9ec11 100644
--- a/src/Module/Update/Profile.php
+++ b/src/Module/Update/Profile.php
@@ -72,7 +72,7 @@ class Profile extends BaseModule
 
 		$condition = ["`uid` = ? AND NOT `contact-blocked` AND NOT `contact-pending`
 				AND `visible` AND (NOT `deleted` OR `gravity` = ?)
-				AND `wall` " . $sql_extra, $a->getProfileOwner(), GRAVITY_ACTIVITY];
+				AND `wall` " . $sql_extra, $a->getProfileOwner(), Item::GRAVITY_ACTIVITY];
 
 		if ($_GET['force'] && !empty($_GET['item'])) {
 			// When the parent is provided, we only fetch this
diff --git a/src/Navigation/Notifications/Factory/FormattedNotify.php b/src/Navigation/Notifications/Factory/FormattedNotify.php
index d4aba639c5..8f0fc5bb1f 100644
--- a/src/Navigation/Notifications/Factory/FormattedNotify.php
+++ b/src/Navigation/Notifications/Factory/FormattedNotify.php
@@ -29,6 +29,7 @@ use Friendica\Core\L10n;
 use Friendica\Core\Protocol;
 use Friendica\Database\Database;
 use Friendica\Model\Contact;
+use Friendica\Model\Item;
 use Friendica\Model\Post;
 use Friendica\Module\BaseNotifications;
 use Friendica\Navigation\Notifications\Collection\FormattedNotifies;
@@ -363,13 +364,13 @@ class FormattedNotify extends BaseFactory
 			$item['author-avatar'] = $item['contact-avatar'];
 		}
 
-		$item['label'] = (($item['gravity'] == GRAVITY_PARENT) ? 'post' : 'comment');
+		$item['label'] = (($item['gravity'] == Item::GRAVITY_PARENT) ? 'post' : 'comment');
 		$item['link']  = $this->baseUrl->get(true) . '/display/' . $item['parent-guid'];
 		$item['image'] = $item['author-avatar'];
 		$item['url']   = $item['author-link'];
 		$item['when']  = DateTimeFormat::local($item['created'], 'r');
 		$item['ago']   = Temporal::getRelativeDate($item['created']);
-		$item['text']  = (($item['gravity'] == GRAVITY_PARENT)
+		$item['text']  = (($item['gravity'] == Item::GRAVITY_PARENT)
 			? $this->l10n->t("%s created a new post", $item['author-name'])
 			: $this->l10n->t("%s commented on %s's post", $item['author-name'], $item['parent-author-name']));
 
diff --git a/src/Object/Api/Mastodon/Status.php b/src/Object/Api/Mastodon/Status.php
index 33ae98eb26..ced6919649 100644
--- a/src/Object/Api/Mastodon/Status.php
+++ b/src/Object/Api/Mastodon/Status.php
@@ -23,6 +23,7 @@ namespace Friendica\Object\Api\Mastodon;
 
 use Friendica\BaseDataTransferObject;
 use Friendica\Content\Text\BBCode;
+use Friendica\Model\Item;
 use Friendica\Object\Api\Mastodon\Status\Counts;
 use Friendica\Object\Api\Mastodon\Status\UserAttributes;
 use Friendica\Util\DateTimeFormat;
@@ -102,7 +103,7 @@ class Status extends BaseDataTransferObject
 		$this->id         = (string)$item['uri-id'];
 		$this->created_at = DateTimeFormat::utc($item['created'], DateTimeFormat::JSON);
 
-		if ($item['gravity'] == GRAVITY_COMMENT) {
+		if ($item['gravity'] == Item::GRAVITY_COMMENT) {
 			$this->in_reply_to_id         = (string)$item['thr-parent-id'];
 			$this->in_reply_to_account_id = (string)$item['parent-author-id'];
 		}
diff --git a/src/Object/Api/Twitter/Status.php b/src/Object/Api/Twitter/Status.php
index 54b4fa2d3b..66f35825a3 100644
--- a/src/Object/Api/Twitter/Status.php
+++ b/src/Object/Api/Twitter/Status.php
@@ -106,7 +106,7 @@ class Status extends BaseDataTransferObject
 
 		$this->created_at = DateTimeFormat::utc($item['created'], DateTimeFormat::API);
 
-		if ($item['gravity'] == GRAVITY_COMMENT) {
+		if ($item['gravity'] == Item::GRAVITY_COMMENT) {
 			$this->in_reply_to_status_id     = (int)$item['thr-parent-id'];
 			$this->in_reply_to_status_id_str = (string)$item['thr-parent-id'];
 			$this->in_reply_to_user_id       = (int)$item['parent-author-id'];
diff --git a/src/Object/Post.php b/src/Object/Post.php
index fe271b5a87..7300fd09b4 100644
--- a/src/Object/Post.php
+++ b/src/Object/Post.php
@@ -210,7 +210,7 @@ class Post
 		$announceable = $shareable && in_array($item['network'], [Protocol::ACTIVITYPUB, Protocol::DFRN, Protocol::DIASPORA, Protocol::TWITTER]);
 
 		// On Diaspora only toplevel posts can be reshared
-		if ($announceable && ($item['network'] == Protocol::DIASPORA) && ($item['gravity'] != GRAVITY_PARENT)) {
+		if ($announceable && ($item['network'] == Protocol::DIASPORA) && ($item['gravity'] != Item::GRAVITY_PARENT)) {
 			$announceable = false;
 		}
 
@@ -915,7 +915,7 @@ class Post
 			return $text;
 		}
 
-		if (($item['author-addr'] != $owner['addr']) && (($item['gravity'] != GRAVITY_PARENT) || !in_array($item['network'], [Protocol::DIASPORA]))) {
+		if (($item['author-addr'] != $owner['addr']) && (($item['gravity'] != Item::GRAVITY_PARENT) || !in_array($item['network'], [Protocol::DIASPORA]))) {
 			$text .= '@' . $item['author-addr'] . ' ';
 		}
 
diff --git a/src/Protocol/ActivityPub/Processor.php b/src/Protocol/ActivityPub/Processor.php
index bb4d61b5af..79626abbb8 100644
--- a/src/Protocol/ActivityPub/Processor.php
+++ b/src/Protocol/ActivityPub/Processor.php
@@ -308,10 +308,10 @@ class Processor
 		$item['thr-parent'] = $activity['reply-to-id'];
 
 		if ($activity['reply-to-id'] == $activity['id']) {
-			$item['gravity'] = GRAVITY_PARENT;
+			$item['gravity'] = Item::GRAVITY_PARENT;
 			$item['object-type'] = Activity\ObjectType::NOTE;
 		} else {
-			$item['gravity'] = GRAVITY_COMMENT;
+			$item['gravity'] = Item::GRAVITY_COMMENT;
 			$item['object-type'] = Activity\ObjectType::COMMENT;
 		}
 
@@ -356,7 +356,7 @@ class Processor
 
 		$item['diaspora_signed_text'] = $activity['diaspora:comment'] ?? '';
 
-		if (empty($conversation) && empty($activity['directmessage']) && ($item['gravity'] != GRAVITY_PARENT) && !Post::exists(['uri' => $item['thr-parent']])) {
+		if (empty($conversation) && empty($activity['directmessage']) && ($item['gravity'] != Item::GRAVITY_PARENT) && !Post::exists(['uri' => $item['thr-parent']])) {
 			Logger::notice('Parent not found, message will be discarded.', ['thr-parent' => $item['thr-parent']]);
 			if (!$fetch_parents) {
 				Queue::remove($activity);
@@ -663,7 +663,7 @@ class Processor
 
 		$item['verb'] = $verb;
 		$item['thr-parent'] = $activity['object_id'];
-		$item['gravity'] = GRAVITY_ACTIVITY;
+		$item['gravity'] = Item::GRAVITY_ACTIVITY;
 		unset($item['post-type']);
 		$item['object-type'] = Activity\ObjectType::NOTE;
 
@@ -833,7 +833,7 @@ class Processor
 			$item['body'] = Item::improveSharedDataInBody($item);
 		} else {
 			$parent_uri = $item['parent-uri'] ?? $item['thr-parent'];
-			if (empty($activity['directmessage']) && ($parent_uri != $item['uri']) && ($item['gravity'] == GRAVITY_COMMENT)) {
+			if (empty($activity['directmessage']) && ($parent_uri != $item['uri']) && ($item['gravity'] == Item::GRAVITY_COMMENT)) {
 				$parent = Post::selectFirst(['id', 'uri-id', 'private', 'author-link', 'alias'], ['uri' => $parent_uri]);
 				if (!DBA::isResult($parent)) {
 					Logger::warning('Unknown parent item.', ['uri' => $parent_uri]);
@@ -937,7 +937,7 @@ class Processor
 			return true;
 		}
 
-		if ($item['gravity'] != GRAVITY_PARENT) {
+		if ($item['gravity'] != Item::GRAVITY_PARENT) {
 			// We cannot reliably check at this point if a comment or activity belongs to an accepted post or needs to be fetched
 			// This can possibly be improved in the future.
 			Logger::debug('Message is no parent - accepted', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
@@ -1035,7 +1035,7 @@ class Processor
 				// When a post arrives via a relay and we follow the author, we have to override the causer.
 				// Otherwise the system assumes that we follow the relay. (See "addRowInformation")
 				Logger::debug('Relay post for follower', ['receiver' => $receiver, 'guid' => $item['guid'], 'relay' => $activity['from-relay']]);
-				$item['causer-id'] = ($item['gravity'] == GRAVITY_PARENT) ? $item['owner-id'] : $item['author-id'];
+				$item['causer-id'] = ($item['gravity'] == Item::GRAVITY_PARENT) ? $item['owner-id'] : $item['author-id'];
 			}
 
 			if ($item['isForum'] ?? false) {
@@ -1053,7 +1053,7 @@ class Processor
 				continue;
 			}
 
-			if (($receiver != 0) && ($item['gravity'] == GRAVITY_PARENT) && !in_array($item['post-reason'], [Item::PR_FOLLOWER, Item::PR_TAG, item::PR_TO, Item::PR_CC])) {
+			if (($receiver != 0) && ($item['gravity'] == Item::GRAVITY_PARENT) && !in_array($item['post-reason'], [Item::PR_FOLLOWER, Item::PR_TAG, item::PR_TO, Item::PR_CC])) {
 				if (!($item['isForum'] ?? false)) {
 					if ($item['post-reason'] == Item::PR_BCC) {
 						Logger::info('Top level post via BCC from a non sharer, ignoring', ['uid' => $receiver, 'contact' => $item['contact-id'], 'url' => $item['uri']]);
@@ -1088,7 +1088,7 @@ class Processor
 				continue;
 			}
 
-			if (($item['gravity'] != GRAVITY_ACTIVITY) && ($activity['object_type'] == 'as:Event')) {
+			if (($item['gravity'] != Item::GRAVITY_ACTIVITY) && ($activity['object_type'] == 'as:Event')) {
 				$event_id = self::createEvent($activity, $item);
 
 				$item = Event::getItemArrayForImportedId($event_id, $item);
@@ -1118,7 +1118,7 @@ class Processor
 		}
 
 		// Store send a follow request for every reshare - but only when the item had been stored
-		if ($stored && ($item['private'] != Item::PRIVATE) && ($item['gravity'] == GRAVITY_PARENT) && !empty($item['author-link']) && ($item['author-link'] != $item['owner-link'])) {
+		if ($stored && ($item['private'] != Item::PRIVATE) && ($item['gravity'] == Item::GRAVITY_PARENT) && !empty($item['author-link']) && ($item['author-link'] != $item['owner-link'])) {
 			$author = APContact::getByURL($item['owner-link'], false);
 			// We send automatic follow requests for reshared messages. (We don't need though for forum posts)
 			if ($author['type'] != 'Group') {
@@ -1138,7 +1138,7 @@ class Processor
 	 */
 	private static function hasParents(array $item, int $receiver)
 	{
-		if (($receiver == 0) || ($item['gravity'] == GRAVITY_PARENT)) {
+		if (($receiver == 0) || ($item['gravity'] == Item::GRAVITY_PARENT)) {
 			return true;
 		}
 
@@ -1149,7 +1149,7 @@ class Processor
 		if ($item['verb'] != Activity::ANNOUNCE) {
 			switch (DI::pConfig()->get($receiver, 'system', 'accept_only_sharer')) {
 				case Item::COMPLETION_COMMENT:
-					$add_parent = ($item['gravity'] != GRAVITY_ACTIVITY);
+					$add_parent = ($item['gravity'] != Item::GRAVITY_ACTIVITY);
 					break;
 
 				case Item::COMPLETION_NONE:
@@ -1283,7 +1283,7 @@ class Processor
 	 */
 	private static function postMail(array $activity, array $item)
 	{
-		if (($item['gravity'] != GRAVITY_PARENT) && !DBA::exists('mail', ['uri' => $item['thr-parent'], 'uid' => $item['uid']])) {
+		if (($item['gravity'] != Item::GRAVITY_PARENT) && !DBA::exists('mail', ['uri' => $item['thr-parent'], 'uid' => $item['uid']])) {
 			Logger::info('Parent not found, mail will be discarded.', ['uid' => $item['uid'], 'uri' => $item['thr-parent']]);
 			return false;
 		}
@@ -1859,7 +1859,7 @@ class Processor
 			return;
 		}
 
-		Item::markForDeletion(['uri' => $activity['object_id'], 'author-id' => $author_id, 'gravity' => GRAVITY_ACTIVITY]);
+		Item::markForDeletion(['uri' => $activity['object_id'], 'author-id' => $author_id, 'gravity' => Item::GRAVITY_ACTIVITY]);
 		Queue::remove($activity);
 	}
 
diff --git a/src/Protocol/ActivityPub/Receiver.php b/src/Protocol/ActivityPub/Receiver.php
index 1ecfaf6aa4..80eb602a0f 100644
--- a/src/Protocol/ActivityPub/Receiver.php
+++ b/src/Protocol/ActivityPub/Receiver.php
@@ -264,7 +264,7 @@ class Receiver
 			}
 		}
 
-		if (Post::exists(['uri' => $object_id, 'gravity' => [GRAVITY_PARENT, GRAVITY_COMMENT]])) {
+		if (Post::exists(['uri' => $object_id, 'gravity' => [Item::GRAVITY_PARENT, Item::GRAVITY_COMMENT]])) {
 			// We just assume "note" since it doesn't make a difference for the further processing
 			return 'as:Note';
 		}
diff --git a/src/Protocol/ActivityPub/Transmitter.php b/src/Protocol/ActivityPub/Transmitter.php
index 11a64504b9..8b07d12e7d 100644
--- a/src/Protocol/ActivityPub/Transmitter.php
+++ b/src/Protocol/ActivityPub/Transmitter.php
@@ -268,7 +268,7 @@ class Transmitter
 		$condition = array_merge($condition, [
 			'uid'           => $owner['uid'],
 			'author-id'      => Contact::getIdForURL($owner['url'], 0, false),
-			'gravity'        => [GRAVITY_PARENT, GRAVITY_COMMENT],
+			'gravity'        => [Item::GRAVITY_PARENT, Item::GRAVITY_COMMENT],
 			'network'        => Protocol::FEDERATED,
 			'parent-network' => Protocol::FEDERATED,
 			'origin'         => true,
@@ -353,7 +353,7 @@ class Transmitter
 			'uid'           => $owner['uid'],
 			'author-id'      => $owner_cid,
 			'private'        => [Item::PUBLIC, Item::UNLISTED],
-			'gravity'        => [GRAVITY_PARENT, GRAVITY_COMMENT],
+			'gravity'        => [Item::GRAVITY_PARENT, Item::GRAVITY_COMMENT],
 			'network'        => Protocol::FEDERATED,
 			'parent-network' => Protocol::FEDERATED,
 			'origin'         => true,
@@ -579,7 +579,7 @@ class Transmitter
 		$item_profile = APContact::getByURL($item['author-link']);
 		$exclude[] = $item['author-link'];
 
-		if ($item['gravity'] == GRAVITY_PARENT) {
+		if ($item['gravity'] == Item::GRAVITY_PARENT) {
 			$exclude[] = $item['owner-link'];
 		}
 
@@ -667,7 +667,7 @@ class Transmitter
 
 		$data = ['to' => [], 'cc' => [], 'bcc' => []];
 
-		if ($item['gravity'] == GRAVITY_PARENT) {
+		if ($item['gravity'] == Item::GRAVITY_PARENT) {
 			$actor_profile = APContact::getByURL($item['owner-link']);
 		} else {
 			$actor_profile = APContact::getByURL($item['author-link']);
@@ -755,10 +755,10 @@ class Transmitter
 		if (!empty($item['parent'])) {
 			$parents = Post::select(['id', 'author-link', 'owner-link', 'gravity', 'uri'], ['parent' => $item['parent']], ['order' => ['id']]);
 			while ($parent = Post::fetch($parents)) {
-				if ($parent['gravity'] == GRAVITY_PARENT) {
+				if ($parent['gravity'] == Item::GRAVITY_PARENT) {
 					$profile = APContact::getByURL($parent['owner-link'], false);
 					if (!empty($profile)) {
-						if ($item['gravity'] != GRAVITY_PARENT) {
+						if ($item['gravity'] != Item::GRAVITY_PARENT) {
 							// Comments to forums are directed to the forum
 							// But comments to forums aren't directed to the followers collection
 							// This rule is only valid when the actor isn't the forum.
@@ -973,7 +973,7 @@ class Transmitter
 
 		$inboxes = [];
 
-		if ($item['gravity'] == GRAVITY_ACTIVITY) {
+		if ($item['gravity'] == Item::GRAVITY_ACTIVITY) {
 			$item_profile = APContact::getByURL($item['author-link'], false);
 		} else {
 			$item_profile = APContact::getByURL($item['owner-link'], false);
@@ -1062,7 +1062,7 @@ class Transmitter
 		$mail['parent-uri']       = $reply['uri'];
 		$mail['parent-uri-id']    = $reply['uri-id'];
 		$mail['parent-author-id'] = Contact::getIdForURL($reply['from-url'], 0, false);
-		$mail['gravity']          = ($mail['reply'] ? GRAVITY_COMMENT: GRAVITY_PARENT);
+		$mail['gravity']          = ($mail['reply'] ? Item::GRAVITY_COMMENT: Item::GRAVITY_PARENT);
 		$mail['event-type']       = '';
 		$mail['language']         = '';
 		$mail['parent']           = 0;
@@ -1247,7 +1247,7 @@ class Transmitter
 		if (!$object_mode) {
 			$data = ['@context' => $context ?? ActivityPub::CONTEXT];
 
-			if ($item['deleted'] && ($item['gravity'] == GRAVITY_ACTIVITY)) {
+			if ($item['deleted'] && ($item['gravity'] == Item::GRAVITY_ACTIVITY)) {
 				$type = 'Undo';
 			} elseif ($item['deleted']) {
 				$type = 'Delete';
@@ -1258,7 +1258,7 @@ class Transmitter
 
 		if ($type == 'Delete') {
 			$data['id'] = Item::newURI($item['guid']) . '/' . $type;;
-		} elseif (($item['gravity'] == GRAVITY_ACTIVITY) && ($type != 'Undo')) {
+		} elseif (($item['gravity'] == Item::GRAVITY_ACTIVITY) && ($type != 'Undo')) {
 			$data['id'] = $item['uri'];
 		} else {
 			$data['id'] = $item['uri'] . '/' . $type;
@@ -1266,7 +1266,7 @@ class Transmitter
 
 		$data['type'] = $type;
 
-		if (($type != 'Announce') || ($item['gravity'] != GRAVITY_PARENT)) {
+		if (($type != 'Announce') || ($item['gravity'] != Item::GRAVITY_PARENT)) {
 			$data['actor'] = $item['author-link'];
 		} else {
 			$data['actor'] = $item['owner-link'];
@@ -1559,7 +1559,7 @@ class Transmitter
 		// We are treating posts differently when they are directed to a community.
 		// This is done to better support Lemmy. Most of the changes should work with other systems as well.
 		// But to not risk compatibility issues we currently perform the changes only for communities.
-		if ($item['gravity'] == GRAVITY_PARENT) {
+		if ($item['gravity'] == Item::GRAVITY_PARENT) {
 			$isCommunityPost = !empty(Tag::getByURIId($item['uri-id'], [Tag::EXCLUSIVE_MENTION]));
 			$links = Post\Media::getByURIId($item['uri-id'], [Post\Media::HTML]);
 			if ($isCommunityPost && (count($links) == 1)) {
diff --git a/src/Protocol/DFRN.php b/src/Protocol/DFRN.php
index 7e92f12927..8fe3c5556e 100644
--- a/src/Protocol/DFRN.php
+++ b/src/Protocol/DFRN.php
@@ -800,7 +800,7 @@ class DFRN
 		$dfrnowner = self::addEntryAuthor($doc, "dfrn:owner", $item["owner-link"], $item);
 		$entry->appendChild($dfrnowner);
 
-		if ($item['gravity'] != GRAVITY_PARENT) {
+		if ($item['gravity'] != Item::GRAVITY_PARENT) {
 			$parent = Post::selectFirst(['guid', 'plink'], ['uri' => $item['thr-parent'], 'uid' => $item['uid']]);
 			if (DBA::isResult($parent)) {
 				$attributes = ["ref" => $item['thr-parent'], "type" => "text/html",
@@ -889,7 +889,7 @@ class DFRN
 
 		if ($item['object-type'] != '') {
 			XML::addElement($doc, $entry, 'activity:object-type', $item['object-type']);
-		} elseif ($item['gravity'] == GRAVITY_PARENT) {
+		} elseif ($item['gravity'] == Item::GRAVITY_PARENT) {
 			XML::addElement($doc, $entry, 'activity:object-type', Activity\ObjectType::NOTE);
 		} else {
 			XML::addElement($doc, $entry, 'activity:object-type', Activity\ObjectType::COMMENT);
@@ -1613,21 +1613,21 @@ class DFRN
 				|| ($item['verb'] == Activity::ATTENDMAYBE)
 				|| ($item['verb'] == Activity::ANNOUNCE)
 			) {
-				$item['gravity'] = GRAVITY_ACTIVITY;
+				$item['gravity'] = Item::GRAVITY_ACTIVITY;
 				// only one like or dislike per person
 				// split into two queries for performance issues
 				$condition = [
-					'uid' => $item['uid'],
-					'author-id' => $item['author-id'],
-					'gravity' => GRAVITY_ACTIVITY,
-					'verb' => $item['verb'],
+					'uid'        => $item['uid'],
+					'author-id'  => $item['author-id'],
+					'gravity'    => Item::GRAVITY_ACTIVITY,
+					'verb'       => $item['verb'],
 					'parent-uri' => $item['thr-parent'],
 				];
 				if (Post::exists($condition)) {
 					return false;
 				}
 
-				$condition = ['uid' => $item['uid'], 'author-id' => $item['author-id'], 'gravity' => GRAVITY_ACTIVITY,
+				$condition = ['uid' => $item['uid'], 'author-id' => $item['author-id'], 'gravity' => Item::GRAVITY_ACTIVITY,
 					'verb' => $item['verb'], 'thr-parent' => $item['thr-parent']];
 				if (Post::exists($condition)) {
 					return false;
@@ -1939,7 +1939,7 @@ class DFRN
 
 		// Now assign the rest of the values that depend on the type of the message
 		if (in_array($entrytype, [self::REPLY, self::REPLY_RC])) {
-			$item['gravity'] = GRAVITY_COMMENT;
+			$item['gravity'] = Item::GRAVITY_COMMENT;
 
 			if (!isset($item['object-type'])) {
 				$item['object-type'] = Activity\ObjectType::COMMENT;
@@ -1965,7 +1965,7 @@ class DFRN
 		if ($entrytype == self::REPLY_RC) {
 			$item['wall'] = 1;
 		} elseif ($entrytype == self::TOP_LEVEL) {
-			$item['gravity'] = GRAVITY_PARENT;
+			$item['gravity'] = Item::GRAVITY_PARENT;
 
 			if (!isset($item['object-type'])) {
 				$item['object-type'] = Activity\ObjectType::NOTE;
@@ -2035,7 +2035,7 @@ class DFRN
 					Logger::info('Contact is not sharing with the user', ['uid' => $item['uid'], 'owner-id' => $item['owner-id'], 'author-id' => $item['author-id'], 'gravity' => $item['gravity'], 'uri' => $item['uri']]);
 					return;
 				}
-				if (($item['gravity'] == GRAVITY_ACTIVITY) && DI::pConfig()->get($item['uid'], 'system', 'accept_only_sharer') == Item::COMPLETION_COMMENT) {
+				if (($item['gravity'] == Item::GRAVITY_ACTIVITY) && DI::pConfig()->get($item['uid'], 'system', 'accept_only_sharer') == Item::COMPLETION_COMMENT) {
 					Logger::info('Completion is set to "comment", but this is an activity. so we stop here.', ['uid' => $item['uid'], 'owner-id' => $item['owner-id'], 'author-id' => $item['author-id'], 'gravity' => $item['gravity'], 'uri' => $item['uri']]);
 					return;
 				}
@@ -2120,13 +2120,13 @@ class DFRN
 		}
 
 		// When it is a starting post it has to belong to the person that wants to delete it
-		if (($item['gravity'] == GRAVITY_PARENT) && ($item['contact-id'] != $importer['id'])) {
+		if (($item['gravity'] == Item::GRAVITY_PARENT) && ($item['contact-id'] != $importer['id'])) {
 			Logger::info('Item with URI ' . $uri . ' do not belong to contact ' . $importer['id'] . ' - ignoring deletion.');
 			return;
 		}
 
 		// Comments can be deleted by the thread owner or comment owner
-		if (($item['gravity'] != GRAVITY_PARENT) && ($item['contact-id'] != $importer['id'])) {
+		if (($item['gravity'] != Item::GRAVITY_PARENT) && ($item['contact-id'] != $importer['id'])) {
 			$condition = ['id' => $item['parent'], 'contact-id' => $importer['id']];
 			if (!Post::exists($condition)) {
 				Logger::info('Item with URI ' . $uri . ' was not found or must not be deleted by contact ' . $importer['id'] . ' - ignoring deletion.');
diff --git a/src/Protocol/Diaspora.php b/src/Protocol/Diaspora.php
index a2c17f4788..ee8edf0a04 100644
--- a/src/Protocol/Diaspora.php
+++ b/src/Protocol/Diaspora.php
@@ -83,7 +83,7 @@ class Diaspora
 		}
 
 		$items = Post::select(['author-id', 'author-link', 'parent-author-link', 'parent-guid', 'guid'],
-			['parent' => $item['parent'], 'gravity' => [GRAVITY_COMMENT, GRAVITY_ACTIVITY]]);
+			['parent' => $item['parent'], 'gravity' => [Item::GRAVITY_COMMENT, Item::GRAVITY_ACTIVITY]]);
 		while ($item = Post::fetch($items)) {
 			$contact = DBA::selectFirst('contact', ['id', 'url', 'name', 'protocol', 'batch', 'network'],
 				['id' => $item['author-id']]);
@@ -1548,7 +1548,7 @@ class Diaspora
 		$datarray['uri-id'] = ItemURI::insert(['uri' => $datarray['uri'], 'guid' => $datarray['guid']]);
 
 		$datarray['verb'] = Activity::POST;
-		$datarray['gravity'] = GRAVITY_COMMENT;
+		$datarray['gravity'] = Item::GRAVITY_COMMENT;
 
 		$datarray['thr-parent'] = $thr_parent ?: $toplevel_parent_item['uri'];
 
@@ -1801,7 +1801,7 @@ class Diaspora
 		$datarray['uri'] = self::getUriFromGuid($author, $guid);
 
 		$datarray['verb'] = $verb;
-		$datarray['gravity'] = GRAVITY_ACTIVITY;
+		$datarray['gravity'] = Item::GRAVITY_ACTIVITY;
 		$datarray['thr-parent'] = $toplevel_parent_item['uri'];
 
 		$datarray['object-type'] = Activity\ObjectType::NOTE;
@@ -1812,7 +1812,7 @@ class Diaspora
 		$datarray['changed'] = $datarray['created'] = $datarray['edited'] = DateTimeFormat::utcNow();
 
 		// like on comments have the comment as parent. So we need to fetch the toplevel parent
-		if ($toplevel_parent_item['gravity'] != GRAVITY_PARENT) {
+		if ($toplevel_parent_item['gravity'] != Item::GRAVITY_PARENT) {
 			$toplevel = Post::selectFirst(['origin'], ['id' => $toplevel_parent_item['parent']]);
 			$origin = $toplevel['origin'];
 		} else {
@@ -1981,7 +1981,7 @@ class Diaspora
 		$datarray['uri'] = self::getUriFromGuid($author, $guid);
 
 		$datarray['verb'] = Activity::FOLLOW;
-		$datarray['gravity'] = GRAVITY_ACTIVITY;
+		$datarray['gravity'] = Item::GRAVITY_ACTIVITY;
 		$datarray['thr-parent'] = $toplevel_parent_item['uri'];
 
 		$datarray['object-type'] = Activity\ObjectType::NOTE;
@@ -2002,9 +2002,9 @@ class Diaspora
 
 		// Send all existing comments and likes to the requesting server
 		$comments = Post::select(['id', 'uri-id', 'parent-author-network', 'author-network', 'verb', 'gravity'],
-			['parent' => $toplevel_parent_item['id'], 'gravity' => [GRAVITY_COMMENT, GRAVITY_ACTIVITY]]);
+			['parent' => $toplevel_parent_item['id'], 'gravity' => [Item::GRAVITY_COMMENT, Item::GRAVITY_ACTIVITY]]);
 		while ($comment = Post::fetch($comments)) {
-			if (($comment['gravity'] == GRAVITY_ACTIVITY) && !in_array($comment['verb'], [Activity::LIKE, Activity::DISLIKE])) {
+			if (($comment['gravity'] == Item::GRAVITY_ACTIVITY) && !in_array($comment['verb'], [Activity::LIKE, Activity::DISLIKE])) {
 				Logger::info('Unsupported activities are not relayed', ['item' => $comment['id'], 'verb' => $comment['verb']]);
 				continue;
 			}
@@ -2302,7 +2302,7 @@ class Diaspora
 		$datarray['thr-parent'] = $parent['uri'];
 
 		$datarray['verb'] = $datarray['body'] = Activity::ANNOUNCE;
-		$datarray['gravity'] = GRAVITY_ACTIVITY;
+		$datarray['gravity'] = Item::GRAVITY_ACTIVITY;
 		$datarray['object-type'] = Activity\ObjectType::NOTE;
 
 		$datarray['protocol'] = $item['protocol'];
@@ -2387,7 +2387,7 @@ class Diaspora
 		$datarray['uri-id'] = ItemURI::insert(['uri' => $datarray['uri'], 'guid' => $datarray['guid']]);
 
 		$datarray['verb'] = Activity::POST;
-		$datarray['gravity'] = GRAVITY_PARENT;
+		$datarray['gravity'] = Item::GRAVITY_PARENT;
 
 		$datarray['protocol'] = Conversation::PARCEL_DIASPORA;
 		$datarray['source'] = $xml;
@@ -2706,7 +2706,7 @@ class Diaspora
 		$datarray['owner-id'] = $datarray['author-id'];
 
 		$datarray['verb'] = Activity::POST;
-		$datarray['gravity'] = GRAVITY_PARENT;
+		$datarray['gravity'] = Item::GRAVITY_PARENT;
 
 		$datarray['protocol'] = Conversation::PARCEL_DIASPORA;
 		$datarray['source'] = $xml;
@@ -3596,7 +3596,7 @@ class Diaspora
 		// - Implicit mentions are enabled
 		if (
 			$item['author-id'] != $thread_parent_item['author-id']
-			&& ($thread_parent_item['gravity'] != GRAVITY_PARENT)
+			&& ($thread_parent_item['gravity'] != Item::GRAVITY_PARENT)
 			&& (empty($item['uid']) || !Feature::isEnabled($item['uid'], 'explicit_mentions'))
 			&& !DI::config()->get('system', 'disable_implicit_mentions')
 		) {
@@ -3729,7 +3729,7 @@ class Diaspora
 
 		$msg_type = 'retraction';
 
-		if ($item['gravity'] == GRAVITY_PARENT) {
+		if ($item['gravity'] == Item::GRAVITY_PARENT) {
 			$target_type = 'Post';
 		} elseif (in_array($item['verb'], [Activity::LIKE, Activity::DISLIKE])) {
 			$target_type = 'Like';
@@ -4069,12 +4069,12 @@ class Diaspora
 			return false;
 		}
 
-		if (($parent_post['gravity'] == GRAVITY_COMMENT) && empty($parent_post['signed_text'])) {
+		if (($parent_post['gravity'] == Item::GRAVITY_COMMENT) && empty($parent_post['signed_text'])) {
 			Logger::info('Parent comment has got no Diaspora signature.', ['parent-id' => $parent_id]);
 			return false;
 		}
 
-		if ($parent_post['gravity'] == GRAVITY_COMMENT) {
+		if ($parent_post['gravity'] == Item::GRAVITY_COMMENT) {
 			return self::parentSupportDiaspora($parent_post['thr-parent-id']);
 		}
 
diff --git a/src/Protocol/Feed.php b/src/Protocol/Feed.php
index 907dfd8b99..e5f205aa5a 100644
--- a/src/Protocol/Feed.php
+++ b/src/Protocol/Feed.php
@@ -254,20 +254,21 @@ class Feed
 			$author['owner-avatar'] = $contact['thumb'];
 		}
 
-		$header = [];
-		$header['uid'] = $importer['uid'] ?? 0;
-		$header['network'] = Protocol::FEED;
+		$header = [
+			'uid'         => $importer['uid'] ?? 0,
+			'network'     => Protocol::FEED,
+			'wall'        => 0,
+			'origin'      => 0,
+			'gravity'     => Item::GRAVITY_PARENT,
+			'private'     => Item::PUBLIC,
+			'verb'        => Activity::POST,
+			'object-type' => Activity\ObjectType::NOTE,
+			'post-type'   => Item::PT_ARTICLE,
+			'contact-id'  => $contact['id'] ?? 0,
+		];
+
 		$datarray['protocol'] = $protocol;
 		$datarray['direction'] = Conversation::PULL;
-		$header['wall'] = 0;
-		$header['origin'] = 0;
-		$header['gravity'] = GRAVITY_PARENT;
-		$header['private'] = Item::PUBLIC;
-		$header['verb'] = Activity::POST;
-		$header['object-type'] = Activity\ObjectType::NOTE;
-		$header['post-type'] = Item::PT_ARTICLE;
-
-		$header['contact-id'] = $contact['id'] ?? 0;
 
 		if (!is_object($entries)) {
 			Logger::info("There are no entries in this feed.");
@@ -956,13 +957,13 @@ class Feed
 
 		$condition = ["`uid` = ? AND `received` > ? AND NOT `deleted` AND `gravity` IN (?, ?)
 			AND `private` != ? AND `visible` AND `wall` AND `parent-network` IN (?, ?, ?, ?)",
-			$owner['uid'], $check_date, GRAVITY_PARENT, GRAVITY_COMMENT,
+			$owner['uid'], $check_date, Item::GRAVITY_PARENT, Item::GRAVITY_COMMENT,
 			Item::PRIVATE, Protocol::ACTIVITYPUB,
 			Protocol::OSTATUS, Protocol::DFRN, Protocol::DIASPORA];
 
 		if ($filter === 'comments') {
 			$condition[0] .= " AND `gravity` = ? ";
-			$condition[] = GRAVITY_COMMENT;
+			$condition[] = Item::GRAVITY_COMMENT;
 		}
 
 		if ($owner['account-type'] != User::ACCOUNT_TYPE_COMMUNITY) {
@@ -1089,7 +1090,7 @@ class Feed
 	 */
 	private static function noteEntry(DOMDocument $doc, array $item, array $owner): DOMElement
 	{
-		if (($item['gravity'] != GRAVITY_PARENT) && (Strings::normaliseLink($item['author-link']) != Strings::normaliseLink($owner['url']))) {
+		if (($item['gravity'] != Item::GRAVITY_PARENT) && (Strings::normaliseLink($item['author-link']) != Strings::normaliseLink($owner['url']))) {
 			Logger::info('Feed entry author does not match feed owner', ['owner' => $owner['url'], 'author' => $item['author-link']]);
 		}
 
@@ -1153,7 +1154,7 @@ class Feed
 	{
 		$mentioned = [];
 
-		if ($item['gravity'] != GRAVITY_PARENT) {
+		if ($item['gravity'] != Item::GRAVITY_PARENT) {
 			$parent = Post::selectFirst(['guid', 'author-link', 'owner-link'], ['id' => $item['parent']]);
 
 			$thrparent = Post::selectFirst(['guid', 'author-link', 'owner-link', 'plink'], ['uid' => $owner['uid'], 'uri' => $item['thr-parent']]);
diff --git a/src/Protocol/OStatus.php b/src/Protocol/OStatus.php
index d01f467ad2..6ec9b9fea1 100644
--- a/src/Protocol/OStatus.php
+++ b/src/Protocol/OStatus.php
@@ -392,7 +392,7 @@ class OStatus
 		$header['network'] = Protocol::OSTATUS;
 		$header['wall'] = 0;
 		$header['origin'] = 0;
-		$header['gravity'] = GRAVITY_COMMENT;
+		$header['gravity'] = Item::GRAVITY_COMMENT;
 
 		if (!is_object($doc->firstChild) || empty($doc->firstChild->tagName)) {
 			return false;
@@ -500,7 +500,7 @@ class OStatus
 
 				$item['verb'] = Activity::LIKE;
 				$item['thr-parent'] = $orig_uri;
-				$item['gravity'] = GRAVITY_ACTIVITY;
+				$item['gravity'] = Item::GRAVITY_ACTIVITY;
 				$item['object-type'] = Activity\ObjectType::NOTE;
 			}
 
@@ -715,7 +715,7 @@ class OStatus
 			}
 		} else {
 			$item['thr-parent'] = $item['uri'];
-			$item['gravity'] = GRAVITY_PARENT;
+			$item['gravity'] = Item::GRAVITY_PARENT;
 		}
 
 		self::$itemlist[] = $item;
@@ -1360,7 +1360,7 @@ class OStatus
 	 */
 	private static function likeEntry(DOMDocument $doc, array $item, array $owner, bool $toplevel): DOMElement
 	{
-		if (($item['gravity'] != GRAVITY_PARENT) && (Strings::normaliseLink($item['author-link']) != Strings::normaliseLink($owner['url']))) {
+		if (($item['gravity'] != Item::GRAVITY_PARENT) && (Strings::normaliseLink($item['author-link']) != Strings::normaliseLink($owner['url']))) {
 			Logger::info('OStatus entry is from author ' . $owner['url'] . ' - not from ' . $item['author-link'] . '. Quitting.');
 		}
 
@@ -1510,7 +1510,7 @@ class OStatus
 	 */
 	private static function noteEntry(DOMDocument $doc, array $item, array $owner, bool $toplevel): DOMElement
 	{
-		if (($item['gravity'] != GRAVITY_PARENT) && (Strings::normaliseLink($item['author-link']) != Strings::normaliseLink($owner['url']))) {
+		if (($item['gravity'] != Item::GRAVITY_PARENT) && (Strings::normaliseLink($item['author-link']) != Strings::normaliseLink($owner['url']))) {
 			Logger::info('OStatus entry is from author ' . $owner['url'] . ' - not from ' . $item['author-link'] . '. Quitting.');
 		}
 
@@ -1640,7 +1640,7 @@ class OStatus
 	{
 		$mentioned = [];
 
-		if ($item['gravity'] != GRAVITY_PARENT) {
+		if ($item['gravity'] != Item::GRAVITY_PARENT) {
 			$parent = Post::selectFirst(['guid', 'author-link', 'owner-link'], ['id' => $item['parent']]);
 
 			$thrparent = Post::selectFirst(['guid', 'author-link', 'owner-link', 'plink'], ['uid' => $owner['uid'], 'uri' => $item['thr-parent']]);
diff --git a/src/Worker/Delivery.php b/src/Worker/Delivery.php
index 32d4887003..fa0121c831 100644
--- a/src/Worker/Delivery.php
+++ b/src/Worker/Delivery.php
@@ -25,18 +25,21 @@ use Friendica\Contact\FriendSuggest\Collection\FriendSuggests;
 use Friendica\Contact\FriendSuggest\Exception\FriendSuggestNotFoundException;
 use Friendica\Core\Logger;
 use Friendica\Core\Protocol;
+use Friendica\Core\Worker;
 use Friendica\Database\DBA;
 use Friendica\DI;
-use Friendica\Model;
+use Friendica\Model\Contact;
+use Friendica\Model\FContact;
+use Friendica\Model\GServer;
+use Friendica\Model\Item;
+use Friendica\Model\Post;
+use Friendica\Model\User;
+use Friendica\Protocol\Activity;
 use Friendica\Protocol\DFRN;
 use Friendica\Protocol\Diaspora;
 use Friendica\Protocol\Email;
-use Friendica\Protocol\Activity;
-use Friendica\Util\Network;
-use Friendica\Core\Worker;
-use Friendica\Model\FContact;
-use Friendica\Model\Item;
 use Friendica\Protocol\Relay;
+use Friendica\Util\Network;
 
 class Delivery
 {
@@ -75,7 +78,7 @@ class Delivery
 			$uid = $post_uriid;
 			$target_item = [];
 		} else {
-			$item = Model\Post::selectFirst(['id', 'parent'], ['uri-id' => $post_uriid, 'uid' => $sender_uid]);
+			$item = Post::selectFirst(['id', 'parent'], ['uri-id' => $post_uriid, 'uid' => $sender_uid]);
 			if (!DBA::isResult($item) || empty($item['parent'])) {
 				Logger::warning('Post not found', ['uri-id' => $post_uriid, 'uid' => $sender_uid]);
 				return;
@@ -85,9 +88,9 @@ class Delivery
 
 			$condition = ['id' => [$target_id, $parent_id], 'visible' => true];
 			$params = ['order' => ['id']];
-			$itemdata = Model\Post::select(Item::DELIVER_FIELDLIST, $condition, $params);
+			$itemdata = Post::select(Item::DELIVER_FIELDLIST, $condition, $params);
 
-			while ($item = Model\Post::fetch($itemdata)) {
+			while ($item = Post::fetch($itemdata)) {
 				if ($item['verb'] == Activity::ANNOUNCE) {
 					continue;
 				}
@@ -124,14 +127,14 @@ class Delivery
 			}
 
 			$condition = ['uri' => $target_item['thr-parent'], 'uid' => $target_item['uid']];
-			$thr_parent = Model\Post::selectFirst(['network', 'object'], $condition);
+			$thr_parent = Post::selectFirst(['network', 'object'], $condition);
 			if (!DBA::isResult($thr_parent)) {
 				// Shouldn't happen. But when this does, we just take the parent as thread parent.
 				// That's totally okay for what we use this variable here.
 				$thr_parent = $parent;
 			}
 
-			if (!empty($contact_id) && Model\Contact::isArchived($contact_id)) {
+			if (!empty($contact_id) && Contact::isArchived($contact_id)) {
 				Logger::info('Contact is archived', ['id' => $contact_id, 'cmd' => $cmd, 'item' => $target_item['id']]);
 				self::setFailedQueue($cmd, $target_item);
 				return;
@@ -144,7 +147,7 @@ class Delivery
 				}
 			}
 
-			$top_level = $target_item['gravity'] == GRAVITY_PARENT;
+			$top_level = $target_item['gravity'] == Item::GRAVITY_PARENT;
 
 			// This is IMPORTANT!!!!
 
@@ -176,7 +179,7 @@ class Delivery
 				&& empty($parent['allow_gid'])
 				&& empty($parent['deny_cid'])
 				&& empty($parent['deny_gid'])
-				&& ($parent["private"] != Model\Item::PRIVATE)) {
+				&& ($parent['private'] != Item::PRIVATE)) {
 				$public_message = true;
 			}
 		}
@@ -185,7 +188,7 @@ class Delivery
 			Logger::warning('No delivery data', ['command' => $cmd, 'uri-id' => $post_uriid, 'cid' => $contact_id]);
 		}
 
-		$owner = Model\User::getOwnerDataById($uid);
+		$owner = User::getOwnerDataById($uid);
 		if (!DBA::isResult($owner)) {
 			self::setFailedQueue($cmd, $target_item);
 			return;
@@ -205,7 +208,7 @@ class Delivery
 			return;
 		}
 
-		$protocol = Model\GServer::getProtocol($contact['gsid'] ?? 0);
+		$protocol = GServer::getProtocol($contact['gsid'] ?? 0);
 
 		// Transmit via Diaspora if the thread had started as Diaspora post.
 		// Also transmit via Diaspora if this is a direct answer to a Diaspora comment.
@@ -250,7 +253,7 @@ class Delivery
 			return;
 		}
 
-		Model\Post\DeliveryData::incrementQueueFailed($item['uri-id'] ?? $item['id']);
+		Post\DeliveryData::incrementQueueFailed($item['uri-id'] ?? $item['id']);
 	}
 
 	/**
@@ -281,7 +284,7 @@ class Delivery
 
 		if ($cmd == self::MAIL) {
 			$item = $target_item;
-			$item['body'] = Model\Item::fixPrivatePhotos($item['body'], $owner['uid'], null, $item['contact-id']);
+			$item['body'] = Item::fixPrivatePhotos($item['body'], $owner['uid'], null, $item['contact-id']);
 			$atom = DFRN::mail($item, $owner);
 		} elseif ($cmd == self::SUGGESTION) {
 			$item = $target_item;
@@ -311,13 +314,13 @@ class Delivery
 
 		Logger::debug('Notifier entry: ' . $contact["url"] . ' ' . (($target_item['guid'] ?? '') ?: $target_item['id']) . ' entry: ' . $atom);
 
-		$protocol = Model\Post\DeliveryData::DFRN;
+		$protocol = Post\DeliveryData::DFRN;
 
 		// We don't have a relationship with contacts on a public post.
 		// Se we transmit with the new method and via Diaspora as a fallback
 		if (!empty($items) && (($items[0]['uid'] == 0) || ($contact['uid'] == 0))) {
 			// Transmit in public if it's a relay post
-			$public_dfrn = ($contact['contact-type'] == Model\Contact::TYPE_RELAY);
+			$public_dfrn = ($contact['contact-type'] == Contact::TYPE_RELAY);
 
 			$deliver_status = DFRN::transmit($owner, $contact, $atom, $public_dfrn);
 
@@ -327,17 +330,17 @@ class Delivery
 
 				if ($cmd == Delivery::POST) {
 					if (($deliver_status >= 200) && ($deliver_status <= 299)) {
-						Model\Post\DeliveryData::incrementQueueDone($target_item['uri-id'], $protocol);
+						Post\DeliveryData::incrementQueueDone($target_item['uri-id'], $protocol);
 
-						Model\GServer::setProtocol($contact['gsid'] ?? 0, $protocol);
+						GServer::setProtocol($contact['gsid'] ?? 0, $protocol);
 					} else {
-						Model\Post\DeliveryData::incrementQueueFailed($target_item['uri-id']);
+						Post\DeliveryData::incrementQueueFailed($target_item['uri-id']);
 					}
 				}
 				return;
 			}
 
-			if ((($deliver_status < 200) || ($deliver_status > 299)) && (empty($server_protocol) || ($server_protocol == Model\Post\DeliveryData::LEGACY_DFRN))) {
+			if ((($deliver_status < 200) || ($deliver_status > 299)) && (empty($server_protocol) || ($server_protocol == Post\DeliveryData::LEGACY_DFRN))) {
 				// Transmit via Diaspora if not possible via Friendica
 				self::deliverDiaspora($cmd, $contact, $owner, $items, $target_item, $public_message, $top_level, $followup);
 				return;
@@ -351,20 +354,20 @@ class Delivery
 
 		if (($deliver_status >= 200) && ($deliver_status <= 299)) {
 			// We successfully delivered a message, the contact is alive
-			Model\Contact::unmarkForArchival($contact);
+			Contact::unmarkForArchival($contact);
 
-			Model\GServer::setProtocol($contact['gsid'] ?? 0, $protocol);
+			GServer::setProtocol($contact['gsid'] ?? 0, $protocol);
 
 			if ($cmd == Delivery::POST) {
-				Model\Post\DeliveryData::incrementQueueDone($target_item['uri-id'], $protocol);
+				Post\DeliveryData::incrementQueueDone($target_item['uri-id'], $protocol);
 			}
 		} else {
 			// The message could not be delivered. We mark the contact as "dead"
-			Model\Contact::markForArchival($contact);
+			Contact::markForArchival($contact);
 
 			Logger::info('Delivery failed: defer message', ['id' => ($target_item['guid'] ?? '') ?: $target_item['id']]);
 			if (!Worker::defer() && $cmd == Delivery::POST) {
-				Model\Post\DeliveryData::incrementQueueFailed($target_item['uri-id']);
+				Post\DeliveryData::incrementQueueFailed($target_item['uri-id']);
 			}
 		}
 	}
@@ -386,7 +389,7 @@ class Delivery
 	private static function deliverDiaspora(string $cmd, array $contact, array $owner, array $items, array $target_item, bool $public_message, bool $top_level, bool $followup)
 	{
 		// We don't treat Forum posts as "wall-to-wall" to be able to post them via Diaspora
-		$walltowall = $top_level && ($owner['id'] != $items[0]['contact-id']) & ($owner['account-type'] != Model\User::ACCOUNT_TYPE_COMMUNITY);
+		$walltowall = $top_level && ($owner['id'] != $items[0]['contact-id']) & ($owner['account-type'] != User::ACCOUNT_TYPE_COMMUNITY);
 
 		if ($public_message) {
 			$loc = 'public batch ' . $contact['batch'];
@@ -438,30 +441,30 @@ class Delivery
 
 		if (($deliver_status >= 200) && ($deliver_status <= 299)) {
 			// We successfully delivered a message, the contact is alive
-			Model\Contact::unmarkForArchival($contact);
+			Contact::unmarkForArchival($contact);
 
-			Model\GServer::setProtocol($contact['gsid'] ?? 0, Model\Post\DeliveryData::DIASPORA);
+			GServer::setProtocol($contact['gsid'] ?? 0, Post\DeliveryData::DIASPORA);
 
 			if ($cmd == Delivery::POST) {
-				Model\Post\DeliveryData::incrementQueueDone($target_item['uri-id'], Model\Post\DeliveryData::DIASPORA);
+				Post\DeliveryData::incrementQueueDone($target_item['uri-id'], Post\DeliveryData::DIASPORA);
 			}
 		} else {
 			// The message could not be delivered. We mark the contact as "dead"
-			Model\Contact::markForArchival($contact);
+			Contact::markForArchival($contact);
 
 			// When it is delivered to the public endpoint, we do mark the relay contact for archival as well
 			if ($public_message) {
 				Relay::markForArchival($contact);
 			}
 
-			if (empty($contact['contact-type']) || ($contact['contact-type'] != Model\Contact::TYPE_RELAY)) {
+			if (empty($contact['contact-type']) || ($contact['contact-type'] != Contact::TYPE_RELAY)) {
 				Logger::info('Delivery failed: defer message', ['id' => ($target_item['guid'] ?? '') ?: $target_item['id']]);
 				// defer message for redelivery
 				if (!Worker::defer() && $cmd == Delivery::POST) {
-					Model\Post\DeliveryData::incrementQueueFailed($target_item['uri-id']);
+					Post\DeliveryData::incrementQueueFailed($target_item['uri-id']);
 				}
 			} elseif ($cmd == Delivery::POST) {
-				Model\Post\DeliveryData::incrementQueueFailed($target_item['uri-id']);
+				Post\DeliveryData::incrementQueueFailed($target_item['uri-id']);
 			}
 		}
 	}
@@ -525,7 +528,7 @@ class Delivery
 
 		// only expose our real email address to true friends
 
-		if (($contact['rel'] == Model\Contact::FRIEND) && !$contact['blocked']) {
+		if (($contact['rel'] == Contact::FRIEND) && !$contact['blocked']) {
 			if ($reply_to) {
 				$headers  = 'From: ' . Email::encodeHeader($local_user['username'],'UTF-8') . ' <' . $reply_to . '>' . "\n";
 				$headers .= 'Sender: ' . $local_user['email'] . "\n";
@@ -551,13 +554,13 @@ class Delivery
 
 			if (empty($target_item['title'])) {
 				$condition = ['uri' => $target_item['parent-uri'], 'uid' => $owner['uid']];
-				$title = Model\Post::selectFirst(['title'], $condition);
+				$title = Post::selectFirst(['title'], $condition);
 
 				if (DBA::isResult($title) && ($title['title'] != '')) {
 					$subject = $title['title'];
 				} else {
 					$condition = ['parent-uri' => $target_item['parent-uri'], 'uid' => $owner['uid']];
-					$title = Model\Post::selectFirst(['title'], $condition);
+					$title = Post::selectFirst(['title'], $condition);
 
 					if (DBA::isResult($title) && ($title['title'] != '')) {
 						$subject = $title['title'];
@@ -575,7 +578,7 @@ class Delivery
 
 		if ($success) {
 			// Success
-			Model\Post\DeliveryData::incrementQueueDone($target_item['uri-id'], Model\Post\DeliveryData::MAIL);
+			Post\DeliveryData::incrementQueueDone($target_item['uri-id'], Post\DeliveryData::MAIL);
 			Logger::info('Delivered via mail', ['guid' => $target_item['guid'], 'to' => $addr, 'subject' => $subject]);
 		} else {
 			// Failed
diff --git a/src/Worker/ExpirePosts.php b/src/Worker/ExpirePosts.php
index ffb40e697e..6f75d18559 100644
--- a/src/Worker/ExpirePosts.php
+++ b/src/Worker/ExpirePosts.php
@@ -68,7 +68,7 @@ class ExpirePosts
 	{
 		Logger::notice('Delete expired posts');
 		// physically remove anything that has been deleted for more than two months
-		$condition = ["`gravity` = ? AND `deleted` AND `changed` < ?", GRAVITY_PARENT, DateTimeFormat::utc('now - 60 days')];
+		$condition = ["`gravity` = ? AND `deleted` AND `changed` < ?", Item::GRAVITY_PARENT, DateTimeFormat::utc('now - 60 days')];
 		$rows = Post::select(['guid', 'uri-id', 'uid'],  $condition);
 		while ($row = Post::fetch($rows)) {
 			Logger::info('Delete expired item', ['uri-id' => $row['uri-id'], 'guid' => $row['guid']]);
@@ -134,7 +134,7 @@ class ExpirePosts
 		}
 
 		$rows = 0;
-		$userposts = DBA::select('post-user', [], ["`gravity` = ? AND `uri-id` not in (select `uri-id` from `post-thread`)", GRAVITY_PARENT]);
+		$userposts = DBA::select('post-user', [], ["`gravity` = ? AND `uri-id` not in (select `uri-id` from `post-thread`)", Item::GRAVITY_PARENT]);
 		while ($fields = DBA::fetch($userposts)) {
 			$post_fields = DI::dbaDefinition()->truncateFieldsForTable('post-thread', $fields);
 			$post_fields['commented'] = $post_fields['changed'] = $post_fields['created'];
@@ -149,7 +149,7 @@ class ExpirePosts
 		}
 
 		$rows = 0;
-		$userposts = DBA::select('post-user', [], ["`gravity` = ? AND `id` not in (select `post-user-id` from `post-thread-user`)", GRAVITY_PARENT]);
+		$userposts = DBA::select('post-user', [], ["`gravity` = ? AND `id` not in (select `post-user-id` from `post-thread-user`)", Item::GRAVITY_PARENT]);
 		while ($fields = DBA::fetch($userposts)) {
 			$post_fields = DI::dbaDefinition()->truncateFieldsForTable('post-thread-user', $fields);
 			$post_fields['commented'] = $post_fields['changed'] = $post_fields['created'];
@@ -264,7 +264,7 @@ class ExpirePosts
 						AND `i`.`parent-uri-id` = `post-user`.`uri-id`)
 					AND NOT `uri-id` IN (SELECT `parent-uri-id` FROM `post-user` AS `i` WHERE `i`.`uid` = ?
 						AND `i`.`parent-uri-id` = `post-user`.`uri-id` AND `i`.`received` > ?))",
-				GRAVITY_PARENT, 0, DateTimeFormat::utc('now - ' . (int)$expire_days_unclaimed . ' days'), 0, 0, DateTimeFormat::utc('now - ' . (int)$expire_days_unclaimed . ' days')]);
+				Item::GRAVITY_PARENT, 0, DateTimeFormat::utc('now - ' . (int)$expire_days_unclaimed . ' days'), 0, 0, DateTimeFormat::utc('now - ' . (int)$expire_days_unclaimed . ' days')]);
 
 			Logger::notice('Start deleting unclaimed public items');
 			$affected_count = 0;
diff --git a/src/Worker/Notifier.php b/src/Worker/Notifier.php
index 45dc4de309..4498723223 100644
--- a/src/Worker/Notifier.php
+++ b/src/Worker/Notifier.php
@@ -143,7 +143,7 @@ class Notifier
 				}
 			}
 
-			$top_level = $target_item['gravity'] == GRAVITY_PARENT;
+			$top_level = $target_item['gravity'] == Item::GRAVITY_PARENT;
 		}
 
 		$owner = User::getOwnerDataById($uid);
diff --git a/tests/datasets/api.fixture.php b/tests/datasets/api.fixture.php
index ace928b090..bafbefd6dc 100644
--- a/tests/datasets/api.fixture.php
+++ b/tests/datasets/api.fixture.php
@@ -387,7 +387,7 @@ return [
 			'uri-id'        => 1,
 			'parent-uri-id' => 1,
 			'thr-parent-id' => 1,
-			'gravity'       => GRAVITY_PARENT,
+			'gravity'       => Item::GRAVITY_PARENT,
 			'network'       => Protocol::DFRN,
 			'owner-id'      => 42,
 			'author-id'     => 42,
@@ -402,7 +402,7 @@ return [
 			'uri-id'        => 2,
 			'parent-uri-id' => 1,
 			'thr-parent-id' => 1,
-			'gravity'       => GRAVITY_COMMENT,
+			'gravity'       => Item::GRAVITY_COMMENT,
 			'network'       => Protocol::DFRN,
 			'owner-id'      => 42,
 			'author-id'     => 42,
@@ -417,7 +417,7 @@ return [
 			'uri-id'        => 3,
 			'parent-uri-id' => 3,
 			'thr-parent-id' => 3,
-			'gravity'       => GRAVITY_PARENT,
+			'gravity'       => Item::GRAVITY_PARENT,
 			'network'       => Protocol::DFRN,
 			'owner-id'      => 42,
 			'author-id'     => 43,
@@ -432,7 +432,7 @@ return [
 			'uri-id'        => 4,
 			'parent-uri-id' => 1,
 			'thr-parent-id' => 1,
-			'gravity'       => GRAVITY_COMMENT,
+			'gravity'       => Item::GRAVITY_COMMENT,
 			'network'       => Protocol::DFRN,
 			'owner-id'      => 42,
 			'author-id'     => 44,
@@ -447,7 +447,7 @@ return [
 			'uri-id'        => 5,
 			'parent-uri-id' => 1,
 			'thr-parent-id' => 1,
-			'gravity'       => GRAVITY_COMMENT,
+			'gravity'       => Item::GRAVITY_COMMENT,
 			'network'       => Protocol::DFRN,
 			'owner-id'      => 42,
 			'author-id'     => 42,
@@ -462,7 +462,7 @@ return [
 			'uri-id'        => 6,
 			'parent-uri-id' => 6,
 			'thr-parent-id' => 6,
-			'gravity'       => GRAVITY_PARENT,
+			'gravity'       => Item::GRAVITY_PARENT,
 			'network'       => Protocol::DFRN,
 			'owner-id'      => 42,
 			'author-id'     => 44,
@@ -477,7 +477,7 @@ return [
 			'uri-id'        => 7,
 			'parent-uri-id' => 7,
 			'thr-parent-id' => 7,
-			'gravity'       => GRAVITY_PARENT,
+			'gravity'       => Item::GRAVITY_PARENT,
 			'network'       => Protocol::DFRN,
 			'owner-id'      => 42,
 			'author-id'     => 44,
@@ -505,7 +505,7 @@ return [
 			'thr-parent-id' => 1,
 			'private'       => Item::PUBLIC,
 			'global'        => true,
-			'gravity'       => GRAVITY_PARENT,
+			'gravity'       => Item::GRAVITY_PARENT,
 			'network'       => Protocol::DFRN,
 			'wall'          => 1,
 			'origin'        => 1,
@@ -519,7 +519,7 @@ return [
 			'origin'        => 1,
 			'parent-uri-id' => 1,
 			'thr-parent-id' => 1,
-			'gravity'       => GRAVITY_COMMENT,
+			'gravity'       => Item::GRAVITY_COMMENT,
 			'network'       => Protocol::DFRN,
 			'owner-id'      => 42,
 			'author-id'     => 42,
@@ -540,7 +540,7 @@ return [
 			'origin'        => 1,
 			'parent-uri-id' => 3,
 			'thr-parent-id' => 3,
-			'gravity'       => GRAVITY_PARENT,
+			'gravity'       => Item::GRAVITY_PARENT,
 			'network'       => Protocol::DFRN,
 			'owner-id'      => 42,
 			'author-id'     => 43,
@@ -561,7 +561,7 @@ return [
 			'origin'        => 1,
 			'parent-uri-id' => 1,
 			'thr-parent-id' => 1,
-			'gravity'       => GRAVITY_COMMENT,
+			'gravity'       => Item::GRAVITY_COMMENT,
 			'network'       => Protocol::DFRN,
 			'owner-id'      => 42,
 			'author-id'     => 44,
@@ -582,7 +582,7 @@ return [
 			'origin'        => 1,
 			'parent-uri-id' => 1,
 			'thr-parent-id' => 1,
-			'gravity'       => GRAVITY_COMMENT,
+			'gravity'       => Item::GRAVITY_COMMENT,
 			'network'       => Protocol::DFRN,
 			'owner-id'      => 42,
 			'author-id'     => 42,
@@ -603,7 +603,7 @@ return [
 			'origin'        => 1,
 			'parent-uri-id' => 6,
 			'thr-parent-id' => 6,
-			'gravity'       => GRAVITY_PARENT,
+			'gravity'       => Item::GRAVITY_PARENT,
 			'network'       => Protocol::DFRN,
 			'owner-id'      => 42,
 			'author-id'     => 44,
@@ -624,7 +624,7 @@ return [
 			'origin'        => 0,
 			'parent-uri-id' => 1,
 			'thr-parent-id' => 1,
-			'gravity'       => GRAVITY_PARENT,
+			'gravity'       => Item::GRAVITY_PARENT,
 			'network'       => Protocol::DFRN,
 			'owner-id'      => 42,
 			'author-id'     => 42,
@@ -645,7 +645,7 @@ return [
 			'origin'        => 0,
 			'parent-uri-id' => 1,
 			'thr-parent-id' => 1,
-			'gravity'       => GRAVITY_COMMENT,
+			'gravity'       => Item::GRAVITY_COMMENT,
 			'network'       => Protocol::DFRN,
 			'owner-id'      => 42,
 			'author-id'     => 42,
@@ -666,7 +666,7 @@ return [
 			'origin'        => 0,
 			'parent-uri-id' => 3,
 			'thr-parent-id' => 3,
-			'gravity'       => GRAVITY_PARENT,
+			'gravity'       => Item::GRAVITY_PARENT,
 			'network'       => Protocol::DFRN,
 			'owner-id'      => 42,
 			'author-id'     => 43,
@@ -687,7 +687,7 @@ return [
 			'origin'        => 0,
 			'parent-uri-id' => 1,
 			'thr-parent-id' => 1,
-			'gravity'       => GRAVITY_COMMENT,
+			'gravity'       => Item::GRAVITY_COMMENT,
 			'network'       => Protocol::DFRN,
 			'owner-id'      => 42,
 			'author-id'     => 44,
@@ -708,7 +708,7 @@ return [
 			'origin'        => 0,
 			'parent-uri-id' => 1,
 			'thr-parent-id' => 1,
-			'gravity'       => GRAVITY_COMMENT,
+			'gravity'       => Item::GRAVITY_COMMENT,
 			'network'       => Protocol::DFRN,
 			'owner-id'      => 42,
 			'author-id'     => 42,
@@ -735,7 +735,7 @@ return [
 			'thr-parent-id' => 6,
 			'private'       => Item::PUBLIC,
 			'global'        => true,
-			'gravity'       => GRAVITY_PARENT,
+			'gravity'       => Item::GRAVITY_PARENT,
 			'network'       => Protocol::DFRN,
 			'origin'        => 0,
 			'deleted'       => 0,
@@ -756,7 +756,7 @@ return [
 			'thr-parent-id' => 7,
 			'private'       => Item::PUBLIC,
 			'global'        => true,
-			'gravity'       => GRAVITY_PARENT,
+			'gravity'       => Item::GRAVITY_PARENT,
 			'network'       => Protocol::DFRN,
 			'origin'        => 0,
 			'deleted'       => 0,
diff --git a/update.php b/update.php
index 9f348efe62..c7e2428af9 100644
--- a/update.php
+++ b/update.php
@@ -299,7 +299,7 @@ function update_1349()
 	}
 
 	if (!DBA::e("UPDATE `item` INNER JOIN `item-activity` ON `item`.`uri-id` = `item-activity`.`uri-id`
-		SET `vid` = `item-activity`.`activity` + 1 WHERE `gravity` = ? AND (`vid` IS NULL OR `vid` = 0)", GRAVITY_ACTIVITY)) {
+		SET `vid` = `item-activity`.`activity` + 1 WHERE `gravity` = ? AND (`vid` IS NULL OR `vid` = 0)", Item::GRAVITY_ACTIVITY)) {
 		return Update::FAILED;
 	}
 
diff --git a/view/theme/frio/theme.php b/view/theme/frio/theme.php
index 4254a99048..863992c40d 100644
--- a/view/theme/frio/theme.php
+++ b/view/theme/frio/theme.php
@@ -33,7 +33,9 @@ use Friendica\Core\Session;
 use Friendica\Database\DBA;
 use Friendica\DI;
 use Friendica\Model;
+use Friendica\Model\Item;
 use Friendica\Model\Contact;
+use Friendica\Model\Profile;
 use Friendica\Module;
 use Friendica\Util\Strings;
 
@@ -203,7 +205,7 @@ function frio_remote_nav(App $a, array &$nav_info)
 {
 	if (DI::mode()->has(App\Mode::MAINTENANCEDISABLED)) {
 		// get the homelink from $_SESSION
-		$homelink = Model\Profile::getMyURL();
+		$homelink = Profile::getMyURL();
 		if (!$homelink) {
 			$homelink = Session::get('visitor_home', '');
 		}
@@ -216,7 +218,7 @@ function frio_remote_nav(App $a, array &$nav_info)
 		} elseif (!local_user() && remote_user()) {
 			$remoteUser                = Contact::getById(remote_user(), $fields);
 			$nav_info['nav']['remote'] = DI::l10n()->t('Guest');
-		} elseif (Model\Profile::getMyURL()) {
+		} elseif (Profile::getMyURL()) {
 			$remoteUser                = Contact::getByURL($homelink, null, $fields);
 			$nav_info['nav']['remote'] = DI::l10n()->t('Visitor');
 		} else {
@@ -257,7 +259,7 @@ function frio_display_item(App $a, &$arr)
 	if (
 		local_user()
 		&& in_array($arr['item']['uid'], [0, local_user()])
-		&& $arr['item']['gravity'] == GRAVITY_PARENT
+		&& $arr['item']['gravity'] == Item::GRAVITY_PARENT
 		&& !$arr['item']['self']
 		&& !$arr['item']['mention']
 	) {