diff --git a/build/code_sniffer/ruleset-php-legacy.xml b/build/code_sniffer/ruleset-php-legacy.xml
index 272c4840b6..b0110e8b12 100644
--- a/build/code_sniffer/ruleset-php-legacy.xml
+++ b/build/code_sniffer/ruleset-php-legacy.xml
@@ -20,6 +20,13 @@
  <!-- Call-time pass-by-reference MUST not be used. -->
  <rule ref="Generic.Functions.CallTimePassByReference.NotAllowed" />
 
+ <!-- Filenames MUST be lowercase. -->
+ <rule ref="Generic.Files.LowercasedFilename" />
+
+ <!-- The function brace MUST be on the line following the function declaration
+      and MUST be indented to the same column as the start of the function declaration. -->
+ <rule ref="Generic.Functions.OpeningFunctionBraceBsdAllman" />
+
  <!-- There MUST be exactly one space after a cast. -->
  <rule ref="Generic.Formatting.SpaceAfterCast" />
 
@@ -35,6 +42,20 @@
  <!-- Each file MUST end with exactly one newline character -->
  <rule ref="PSR2.Files.EndFileNewline" />
 
+ <!-- When referencing arrays there MUST NOT be any whitespace around the opening bracket
+      or before the closing bracket. -->
+ <rule ref="Squiz.Arrays.ArrayBracketSpacing" />
+
+ <!-- The "else if" statement MUST be written with a space between the words else and if. -->
+ <rule ref="Squiz.ControlStructures.ElseIfDeclaration" />
+
+ <!-- There MUST be a space between each element of a foreach loop. -->
+ <rule ref="Squiz.ControlStructures.ForEachLoopDeclaration" />
+
+ <!-- In a for loop declaration, there MUST be no space inside the brackets
+      and there MUST be 0 spaces before and 1 space after semicolons. -->
+ <rule ref="Squiz.ControlStructures.ForLoopDeclaration" />
+
  <!-- In the argument list, there MUST NOT be a space before each comma,
       and there MUST be one space after each comma. -->
  <rule ref="Squiz.Functions.FunctionDeclarationArgumentSpacing">
@@ -44,6 +65,9 @@
  </rule>
  <rule ref="Squiz.Functions.FunctionDeclarationArgumentSpacing.SpacingAfterHint" />
 
+ <!-- All built-in PHP functions MUST be called lowercased. -->
+ <rule ref="Squiz.Functions.LowercaseFunctionKeywords" />
+
  <!-- The eval() function MUST NOT be used. -->
  <rule ref="Squiz.PHP.Eval" />
 
diff --git a/build/code_sniffer/ruleset-php-strict.xml b/build/code_sniffer/ruleset-php-strict.xml
index f2d5b86dd1..c722f7851c 100644
--- a/build/code_sniffer/ruleset-php-strict.xml
+++ b/build/code_sniffer/ruleset-php-strict.xml
@@ -22,6 +22,9 @@
  <!-- PHP keywords MUST be in lower case. -->
  <rule ref="Generic.PHP.LowerCaseKeyword" />
 
+ <!-- Constructors MUST be called __construct() instead of after the class. -->
+ <rule ref="Generic.NamingConventions.ConstructorName" />
+
  <!-- Classes etc. MUST be namespaced -->
  <rule ref="PSR1.Classes.ClassDeclaration.MissingNamespace" />
 
diff --git a/phpBB/includes/acp/acp_extensions.php b/phpBB/includes/acp/acp_extensions.php
index 3d3cfb7f16..b2a6820461 100644
--- a/phpBB/includes/acp/acp_extensions.php
+++ b/phpBB/includes/acp/acp_extensions.php
@@ -527,7 +527,7 @@ class acp_extensions
 
 		$version_helper = new \phpbb\version_helper($this->cache, $this->config, $this->user);
 		$version_helper->set_current_version($meta['version']);
-		$version_helper->set_file_location($version_check ['host'], $version_check ['directory'], $version_check ['filename']);
+		$version_helper->set_file_location($version_check['host'], $version_check['directory'], $version_check['filename']);
 		$version_helper->force_stability($this->config['extension_force_unstable'] ? 'unstable' : null);
 
 		return $updates = $version_helper->get_suggested_updates($force_update, $force_cache);
diff --git a/phpBB/includes/functions_convert.php b/phpBB/includes/functions_convert.php
index e8f8151d6f..9005c57c8a 100644
--- a/phpBB/includes/functions_convert.php
+++ b/phpBB/includes/functions_convert.php
@@ -2297,7 +2297,7 @@ function convert_bbcode($message, $convert_size = true, $extended_bbcodes = fals
 		$message = preg_replace('#\[size=([0-9]+)\](.*?)\[/size\]#i', '[size=\1]\2[/size]', $message);
 		$message = preg_replace('#\[size=[0-9]{2,}\](.*?)\[/size\]#i', '[size=29]\1[/size]', $message);
 
-		for ($i = sizeof($size); $i; )
+		for ($i = sizeof($size); $i;)
 		{
 			$i--;
 			$message = str_replace('[size=' . $i . ']', '[size=' . $size[$i] . ']', $message);
diff --git a/phpBB/includes/mcp/mcp_main.php b/phpBB/includes/mcp/mcp_main.php
index 9a2b4d2a4e..84097327bd 100644
--- a/phpBB/includes/mcp/mcp_main.php
+++ b/phpBB/includes/mcp/mcp_main.php
@@ -496,11 +496,11 @@ function mcp_move_topic($topic_ids)
 			{
 				$topics_moved++;
 			}
-			elseif ($topic_info['topic_visibility'] == ITEM_UNAPPROVED || $topic_info['topic_visibility'] == ITEM_REAPPROVE)
+			else if ($topic_info['topic_visibility'] == ITEM_UNAPPROVED || $topic_info['topic_visibility'] == ITEM_REAPPROVE)
 			{
 				$topics_moved_unapproved++;
 			}
-			elseif ($topic_info['topic_visibility'] == ITEM_DELETED)
+			else if ($topic_info['topic_visibility'] == ITEM_DELETED)
 			{
 				$topics_moved_softdeleted++;
 			}
diff --git a/phpBB/includes/mcp/mcp_reports.php b/phpBB/includes/mcp/mcp_reports.php
index f045fd018f..b0148356ce 100644
--- a/phpBB/includes/mcp/mcp_reports.php
+++ b/phpBB/includes/mcp/mcp_reports.php
@@ -489,7 +489,7 @@ function close_report($report_id_list, $mode, $action, $pm = false)
 	{
 		$redirect = request_var('redirect', build_url(array('mode', 'r', 'quickmod')) . '&amp;mode=reports');
 	}
-	elseif ($action == 'delete' && strpos($user->data['session_page'], 'mode=pm_report_details') !== false)
+	else if ($action == 'delete' && strpos($user->data['session_page'], 'mode=pm_report_details') !== false)
 	{
 		$redirect = request_var('redirect', build_url(array('mode', 'r', 'quickmod')) . '&amp;mode=pm_reports');
 	}
diff --git a/phpBB/phpbb/auth/provider_collection.php b/phpBB/phpbb/auth/provider_collection.php
index 27a3f24564..fe32a34e12 100644
--- a/phpBB/phpbb/auth/provider_collection.php
+++ b/phpBB/phpbb/auth/provider_collection.php
@@ -53,7 +53,7 @@ class provider_collection extends \phpbb\di\service_collection
 			return $this->offsetGet('auth.provider.' . basename(trim($this->config['auth_method'])));
 		}
 		// Revert to db auth provider if selected method does not exist
-		elseif ($this->offsetExists('auth.provider.db'))
+		else if ($this->offsetExists('auth.provider.db'))
 		{
 			return $this->offsetGet('auth.provider.db');
 		}
diff --git a/phpBB/phpbb/avatar/driver/upload.php b/phpBB/phpbb/avatar/driver/upload.php
index 7f77db5949..c43004f340 100644
--- a/phpBB/phpbb/avatar/driver/upload.php
+++ b/phpBB/phpbb/avatar/driver/upload.php
@@ -72,7 +72,7 @@ class upload extends \phpbb\avatar\driver\driver
 		{
 			$file = $upload->form_upload('avatar_upload_file');
 		}
-		elseif (!empty($this->config['allow_avatar_remote_upload']) && !empty($url))
+		else if (!empty($this->config['allow_avatar_remote_upload']) && !empty($url))
 		{
 			if (!preg_match('#^(http|https|ftp)://#i', $url))
 			{
diff --git a/phpBB/phpbb/cache/driver/file.php b/phpBB/phpbb/cache/driver/file.php
index 03b7b1ea82..b32af32d25 100644
--- a/phpBB/phpbb/cache/driver/file.php
+++ b/phpBB/phpbb/cache/driver/file.php
@@ -224,7 +224,7 @@ class file extends \phpbb\cache\driver\base
 			{
 				$this->remove_dir($fileInfo->getPathname());
 			}
-			elseif (strpos($filename, 'container_') === 0 ||
+			else if (strpos($filename, 'container_') === 0 ||
 				strpos($filename, 'url_matcher') === 0 ||
 				strpos($filename, 'sql_') === 0 ||
 				strpos($filename, 'data_') === 0)
diff --git a/phpBB/phpbb/console/command/config/get.php b/phpBB/phpbb/console/command/config/get.php
index 20164f0da1..ee8c65110e 100644
--- a/phpBB/phpbb/console/command/config/get.php
+++ b/phpBB/phpbb/console/command/config/get.php
@@ -60,7 +60,7 @@ class get extends command
 		{
 			$output->write($this->config[$key]);
 		}
-		elseif (isset($this->config[$key]))
+		else if (isset($this->config[$key]))
 		{
 			$output->writeln($this->config[$key]);
 		}
diff --git a/phpBB/phpbb/db/driver/mssqlnative.php b/phpBB/phpbb/db/driver/mssqlnative.php
index 9639bfa988..a7f93c8feb 100644
--- a/phpBB/phpbb/db/driver/mssqlnative.php
+++ b/phpBB/phpbb/db/driver/mssqlnative.php
@@ -319,10 +319,10 @@ class mssqlnative extends \phpbb\db\driver\mssql_base
 			{
 				foreach ($errors as $error)
 				{
-					$error_message .= "SQLSTATE: " . $error[ 'SQLSTATE'] . "\n";
-					$error_message .= "code: " . $error[ 'code'] . "\n";
+					$error_message .= "SQLSTATE: " . $error['SQLSTATE'] . "\n";
+					$error_message .= "code: " . $error['code'] . "\n";
 					$code = $error['code'];
-					$error_message .= "message: " . $error[ 'message'] . "\n";
+					$error_message .= "message: " . $error['message'] . "\n";
 				}
 				$this->last_error_result = $error_message;
 				$error = $this->last_error_result;
diff --git a/phpBB/phpbb/event/recursive_event_filter_iterator.php b/phpBB/phpbb/event/recursive_event_filter_iterator.php
index f65feff448..64e2e56f6a 100644
--- a/phpBB/phpbb/event/recursive_event_filter_iterator.php
+++ b/phpBB/phpbb/event/recursive_event_filter_iterator.php
@@ -39,7 +39,8 @@ class recursive_event_filter_iterator extends \RecursiveFilterIterator
 	*
 	* @return recursive_event_filter_iterator
 	*/
-	public function getChildren() {
+	public function getChildren()
+	{
 		return new self($this->getInnerIterator()->getChildren(), $this->root_path);
 	}
 
diff --git a/phpBB/phpbb/passwords/helper.php b/phpBB/phpbb/passwords/helper.php
index c6c5fb6d02..c2a49202cd 100644
--- a/phpBB/phpbb/passwords/helper.php
+++ b/phpBB/phpbb/passwords/helper.php
@@ -60,7 +60,7 @@ class helper
 			$data[$type] .= ($data[$type] !== '$') ? '\\' : '';
 			$data[$type] .= str_replace('$', '', $value);
 		}
-		elseif ($type == 'settings')
+		else if ($type == 'settings')
 		{
 			$data[$type] .= ($data[$type] !== '$') ? '$' : '';
 			$data[$type] .= $value;
diff --git a/phpBB/phpbb/search/fulltext_postgres.php b/phpBB/phpbb/search/fulltext_postgres.php
index 49d528c8ba..bdb5a86009 100644
--- a/phpBB/phpbb/search/fulltext_postgres.php
+++ b/phpBB/phpbb/search/fulltext_postgres.php
@@ -263,12 +263,12 @@ class fulltext_postgres extends \phpbb\search\base
 					$this->search_query .= $word . ' ';
 					$this->tsearch_query .= '&' . substr($word, 1) . ' ';
 				}
-				elseif (strpos($word, '-') === 0)
+				else if (strpos($word, '-') === 0)
 				{
 					$this->search_query .= $word . ' ';
 					$this->tsearch_query .= '&!' . substr($word, 1) . ' ';
 				}
-				elseif (strpos($word, '|') === 0)
+				else if (strpos($word, '|') === 0)
 				{
 					$this->search_query .= $word . ' ';
 					$this->tsearch_query .= '|' . substr($word, 1) . ' ';
diff --git a/phpBB/search.php b/phpBB/search.php
index 91ea21909d..f1f02ac766 100644
--- a/phpBB/search.php
+++ b/phpBB/search.php
@@ -1256,7 +1256,7 @@ $s_characters .= '<option value="0">0</option>';
 $s_characters .= '<option value="25">25</option>';
 $s_characters .= '<option value="50">50</option>';
 
-for ($i = 100; $i <= 1000 ; $i += 100)
+for ($i = 100; $i <= 1000; $i += 100)
 {
 	$selected = ($i == 300) ? ' selected="selected"' : '';
 	$s_characters .= '<option value="' . $i . '"' . $selected . '>' . $i . '</option>';