diff --git a/phpBB/includes/functions_admin.php b/phpBB/includes/functions_admin.php
index a990a084e7..697b5bfa2a 100644
--- a/phpBB/includes/functions_admin.php
+++ b/phpBB/includes/functions_admin.php
@@ -1841,9 +1841,9 @@ function sync($mode, $where_type = '', $where_ids = '', $resync_parents = false,
 				*
 				* @event core.sync_forum_last_post_info_sql
 				* @var	array	sql_ary		SQL array with some post and user data from the last posts list
-				* @since 3.2.6-RC1
+				* @since 3.3.3-RC1
 				*/
-				$vars = array('sql_ary');
+				$vars = ['sql_ary'];
 				extract($phpbb_dispatcher->trigger_event('core.sync_forum_last_post_info_sql', compact($vars)));
 				$result = $db->sql_query($db->sql_build_query('SELECT', $sql_ary));
 
@@ -1894,13 +1894,13 @@ function sync($mode, $where_type = '', $where_ids = '', $resync_parents = false,
 			* @var	array	forum_data		Array with data to update for all forum ids
 			* @var	array	post_info		Array with some post and user data from the last posts list
 			* @var	array	fieldnames		Array with the partial column names that are being updated
-			* @since 3.2.6-RC1
+			* @since 3.3.3-RC1
 			*/
-			$vars = array(
+			$vars = [
 				'forum_data',
 				'post_info',
 				'fieldnames',
-			);
+			];
 			extract($phpbb_dispatcher->trigger_event('core.sync_modify_forum_data', compact($vars)));
 			unset($post_info);
 
@@ -2082,19 +2082,19 @@ function sync($mode, $where_type = '', $where_ids = '', $resync_parents = false,
 					AND u.user_id = p.poster_id',
 			);
 
-			$custom_fieldnames = array();
+			$custom_fieldnames = [];
 			/**
 			* Event to modify the SQL array to get the post and user data from all topics' last posts
 			*
 			* @event core.sync_topic_last_post_info_sql
 			* @var	array	sql_ary					SQL array with some post and user data from the last posts list
 			* @var	array	custom_fieldnames		Empty array for custom fieldnames to update the topics_table with
-			* @since 3.2.6-RC1
+			* @since 3.3.1-RC1
 			*/
-			$vars = array(
+			$vars = [
 				'sql_ary',
 				'custom_fieldnames',
-			);
+			];
 			extract($phpbb_dispatcher->trigger_event('core.sync_topic_last_post_info_sql', compact($vars)));
 			$result = $db->sql_query($db->sql_build_query('SELECT', $sql_ary));
 
@@ -2126,13 +2126,13 @@ function sync($mode, $where_type = '', $where_ids = '', $resync_parents = false,
 				* @var	array	topic_data		Array with the topics' data we are syncing
 				* @var	array	row				Array with some of the current user and post data
 				* @var	int		topic_id		The current topic_id of $row
-				* @since 3.2.6-RC1
+				* @since 3.3.1-RC1
 				*/
-				$vars = array(
+				$vars = [
 					'topic_data',
 					'row',
 					'topic_id',
-				);
+				];
 				extract($phpbb_dispatcher->trigger_event('core.sync_modify_topic_data', compact($vars)));
 			}
 			$db->sql_freeresult($result);
@@ -2251,6 +2251,7 @@ function sync($mode, $where_type = '', $where_ids = '', $resync_parents = false,
 
 			// Add custom fieldnames
 			$fieldnames = array_merge($fieldnames, $custom_fieldnames);
+			unset($custom_fieldnames);
 
 			if ($sync_extra)
 			{
diff --git a/phpBB/includes/functions_posting.php b/phpBB/includes/functions_posting.php
index ad394154ce..b14533b002 100644
--- a/phpBB/includes/functions_posting.php
+++ b/phpBB/includes/functions_posting.php
@@ -356,12 +356,12 @@ function update_post_information($type, $ids, $return_update_sql = false)
 		* @event core.update_post_info_modify_posts_sql
 		* @var	string	type				The table being updated (forum or topic)
 		* @var	array	sql_ary				SQL array to get some of the last posts' data
-		* @since 3.2.6-RC1
+		* @since 3.3.3-RC1
 		*/
-		$vars = array(
+		$vars = [
 			'type',
 			'sql_ary',
-		);
+		];
 		extract($phpbb_dispatcher->trigger_event('core.update_post_info_modify_posts_sql', compact($vars)));
 		$result = $db->sql_query($db->sql_build_query('SELECT', $sql_ary));
 
@@ -385,14 +385,15 @@ function update_post_information($type, $ids, $return_update_sql = false)
 		* @var	string	type				The table being updated (forum or topic)
 		* @var	array	rowset				Array with the posts data
 		* @var	array	update_sql			Array with SQL data to update the forums or topics table with
-		* @since 3.2.6-RC1
+		* @since 3.3.3-RC1
 		*/
-		$vars = array(
+		$vars = [
 			'type',
 			'rowset',
 			'update_sql',
-		);
+		];
 		extract($phpbb_dispatcher->trigger_event('core.update_post_info_modify_sql', compact($vars)));
+		unset($rowset);
 	}
 	unset($empty_forums, $ids, $last_post_ids);
 
diff --git a/phpBB/includes/mcp/mcp_main.php b/phpBB/includes/mcp/mcp_main.php
index a3fa0b20d9..9d62074341 100644
--- a/phpBB/includes/mcp/mcp_main.php
+++ b/phpBB/includes/mcp/mcp_main.php
@@ -1573,15 +1573,15 @@ function mcp_fork_topic($topic_ids)
 				* @var	array	sql_ary			SQL Array with the post's data
 				* @var	array	row				Post data
 				* @var	array	counter			Array with post counts
-				* @since 3.2.6-RC1
+				* @since 3.3.3-RC1
 				*/
-				$vars = array(
+				$vars = [
 					'new_topic_id',
 					'to_forum_id',
 					'sql_ary',
 					'row',
 					'counter',
-				);
+				];
 				extract($phpbb_dispatcher->trigger_event('core.mcp_main_modify_fork_post_sql', compact($vars)));
 				$db->sql_query('INSERT INTO ' . POSTS_TABLE . ' ' . $db->sql_build_array('INSERT', $sql_ary));
 				$new_post_id = $db->sql_nextid();