diff --git a/inc/statifyblacklist-admin.class.php b/inc/class-statifyblacklist-admin.php
similarity index 79%
rename from inc/statifyblacklist-admin.class.php
rename to inc/class-statifyblacklist-admin.php
index 2b819e4..f436f23 100644
--- a/inc/statifyblacklist-admin.class.php
+++ b/inc/class-statifyblacklist-admin.php
@@ -10,7 +10,7 @@
  */
 
 // Quit.
-defined( 'ABSPATH' ) or exit;
+defined( 'ABSPATH' ) || exit;
 
 /**
  * Statify Blacklist admin configuration.
@@ -29,22 +29,26 @@ class StatifyBlacklist_Admin extends StatifyBlacklist {
 	public static function update_options( $options = null ) {
 		if ( isset( $options ) && current_user_can( 'manage_options' ) ) {
 			// Sanitize URLs and remove empty inputs.
-			$givenReferer = $options['referer']['blacklist'];
+			$given_referer = $options['referer']['blacklist'];
 			if ( 0 === $options['referer']['regexp'] ) {
-				$sanitizedReferer = self::sanitizeURLs( $givenReferer );
+				$sanitized_referer = self::sanitizeURLs( $given_referer );
 			} else {
-				$sanitizedReferer = $givenReferer;
+				$sanitized_referer = $given_referer;
 			}
 
 			// Sanitize IPs and Subnets and remove empty inputs.
-			$givenIP     = $options['ip']['blacklist'];
-			$sanitizedIP = self::sanitizeIPs( $givenIP );
+			$given_ip     = $options['ip']['blacklist'];
+			$sanitized_ip = self::sanitizeIPs( $given_ip );
 
 			// Abort on errors.
-			if ( ! empty( array_diff( array_keys( $givenReferer ), array_keys( $sanitizedReferer ) ) ) ) {
-				return array( 'referer' => $sanitizedReferer );
-			} elseif ( ! empty( array_diff( $givenIP, $sanitizedIP ) ) ) {
-				return array( 'ip' => array_diff( $givenIP, $sanitizedIP ) );
+			if ( ! empty( array_diff( array_keys( $given_referer ), array_keys( $sanitized_referer ) ) ) ) {
+				return array(
+					'referer' => $sanitized_referer,
+				);
+			} elseif ( ! empty( array_diff( $given_ip, $sanitized_ip ) ) ) {
+				return array(
+					'ip' => array_diff( $given_ip, $sanitized_ip ),
+					);
 			}
 
 			// Update database on success.
@@ -150,58 +154,60 @@ class StatifyBlacklist_Admin extends StatifyBlacklist {
 		}
 
 		if ( defined( 'DOING_CRON' ) && DOING_CRON ) {
-			$cleanRef = ( 1 === self::$_options['referer']['cron'] );
-			$cleanTrg = ( 1 === self::$_options['target']['cron'] );
+			$clean_ref = ( 1 === self::$_options['referer']['cron'] );
+			$clean_trg = ( 1 === self::$_options['target']['cron'] );
 		} else {
-			$cleanRef = true;
-			$cleanTrg = true;
+			$clean_ref = true;
+			$clean_trg = true;
 		}
 
-		if ( $cleanRef ) {
+		if ( $clean_ref ) {
 			if ( isset( self::$_options['referer']['regexp'] ) && self::$_options['referer']['regexp'] > 0 ) {
 				// Merge given regular expressions into one.
-				$refererRegexp = implode( '|', array_keys( self::$_options['referer']['blacklist'] ) );
+				$referer_regexp = implode( '|', array_keys( self::$_options['referer']['blacklist'] ) );
 			} else {
 				// Sanitize URLs.
 				$referer = self::sanitizeURLs( self::$_options['referer']['blacklist'] );
 
 				// Build filter regexp.
-				$refererRegexp = str_replace( '.', '\.', implode( '|', array_flip( $referer ) ) );
+				$referer_regexp = str_replace( '.', '\.', implode( '|', array_flip( $referer ) ) );
 			}
 		}
 
-		if ( $cleanTrg ) {
+		if ( $clean_trg ) {
 			if ( isset( self::$_options['target']['regexp'] ) && self::$_options['target']['regexp'] > 0 ) {
 				// Merge given regular expressions into one.
-				$targetRegexp = implode( '|', array_keys( self::$_options['target']['blacklist'] ) );
+				$target_regexp = implode( '|', array_keys( self::$_options['target']['blacklist'] ) );
 			} else {
 				// Build filter regexp.
-				$targetRegexp = str_replace( '.', '\.', implode( '|', array_flip( self::$_options['target']['blacklist'] ) ) );
+				$target_regexp = str_replace( '.', '\.', implode( '|', array_flip( self::$_options['target']['blacklist'] ) ) );
 			}
 		}
 
-		if ( ! empty( $refererRegexp ) || ! empty( $targetRegexp ) ) {
+		if ( ! empty( $referer_regexp ) || ! empty( $target_regexp ) ) {
 			global $wpdb;
 
 			// Execute filter on database.
-			if ( ! empty( $refererRegexp ) ) {
+			// @codingStandardsIgnoreStart These statements prouce warnings, rework in future release (TODO).
+			if ( ! empty( $referer_regexp ) ) {
 				$wpdb->query(
 					$wpdb->prepare(
 						"DELETE FROM `$wpdb->statify` WHERE "
 						. ( ( 1 === self::$_options['referer']['regexp'] ) ? ' BINARY ' : '' )
-						. 'referrer REGEXP %s', $refererRegexp
+						. 'referrer REGEXP %s', $referer_regexp
 					)
 				);
 			}
-			if ( ! empty( $targetRegexp ) ) {
+			if ( ! empty( $target_regexp ) ) {
 				$wpdb->query(
 					$wpdb->prepare(
 						"DELETE FROM `$wpdb->statify` WHERE "
 						. ( ( 1 === self::$_options['target']['regexp'] ) ? ' BINARY ' : '' )
-						. 'target REGEXP %s', $targetRegexp
+						. 'target REGEXP %s', $target_regexp
 					)
 				);
 			}
+			// @codingStandardsIgnoreEnd
 
 			// Optimize DB.
 			$wpdb->query( "OPTIMIZE TABLE `$wpdb->statify`" );
diff --git a/inc/statifyblacklist-system.class.php b/inc/class-statifyblacklist-system.php
similarity index 94%
rename from inc/statifyblacklist-system.class.php
rename to inc/class-statifyblacklist-system.php
index 9ec589b..7dac2f0 100644
--- a/inc/statifyblacklist-system.class.php
+++ b/inc/class-statifyblacklist-system.php
@@ -10,7 +10,7 @@
  */
 
 // Quit.
-defined( 'ABSPATH' ) or exit;
+defined( 'ABSPATH' ) || exit;
 
 /**
  * Statify Blacklist system configuration.
@@ -32,7 +32,8 @@ class StatifyBlacklist_System extends StatifyBlacklist {
 			if ( function_exists( 'get_sites' ) ) {
 				$sites = get_sites();
 			} elseif ( function_exists( 'wp_get_sites' ) ) {
-				$sites = wp_get_sites();    // Legacy support for WP < 4.6.
+				// @codingStandardsIgnoreLine Legacy support for WP < 4.6.
+				$sites = wp_get_sites();
 			} else {
 				return;
 			}
@@ -67,7 +68,8 @@ class StatifyBlacklist_System extends StatifyBlacklist {
 			if ( function_exists( 'get_sites' ) ) {
 				$sites = get_sites();
 			} elseif ( function_exists( 'wp_get_sites' ) ) {
-				$sites = wp_get_sites();    // Legacy support for WP < 4.6.
+				// @codingStandardsIgnoreLine Legacy support for WP < 4.6.
+				$sites = wp_get_sites();
 			} else {
 				return;
 			}
diff --git a/inc/statifyblacklist.class.php b/inc/class-statifyblacklist.php
similarity index 91%
rename from inc/statifyblacklist.class.php
rename to inc/class-statifyblacklist.php
index 0a2144d..3b2a7b2 100644
--- a/inc/statifyblacklist.class.php
+++ b/inc/class-statifyblacklist.php
@@ -9,7 +9,7 @@
  */
 
 // Quit.
-defined( 'ABSPATH' ) or exit;
+defined( 'ABSPATH' ) || exit;
 
 /**
  * Statify Blacklist.
@@ -58,7 +58,7 @@ class StatifyBlacklist {
 	 */
 	public function __construct() {
 		// Skip on autosave or AJAX.
-		if ( ( defined( 'DOING_AUTOSAVE' ) && DOING_AUTOSAVE ) or ( defined( 'DOING_AJAX' ) && DOING_AJAX ) ) {
+		if ( ( defined( 'DOING_AUTOSAVE' ) && DOING_AUTOSAVE ) || ( defined( 'DOING_AJAX' ) && DOING_AJAX ) ) {
 			return;
 		}
 
@@ -223,7 +223,8 @@ class StatifyBlacklist {
 
 		// IP blacklist (since 1.4.0).
 		if ( isset( self::$_options['ip']['active'] ) && 0 !== self::$_options['ip']['active'] ) {
-			if ( false !== ( $ip = self::get_ip() ) ) {
+			$ip = self::get_ip();
+			if ( false !== ( $ip ) ) {
 				foreach ( self::$_options['ip']['blacklist'] as $net ) {
 					if ( self::cidr_match( $ip, $net ) ) {
 						return true;
@@ -247,14 +248,15 @@ class StatifyBlacklist {
 	 */
 	private static function get_ip() {
 		foreach (
+
+			/*
+			 * There are more fields, that could possibly be checked, but we only consider the most common for now:
+			 * HTTP_CLIENT_IP, HTTP_X_REAL_IP, HTTP_X_FORWARDED_FOR, HTTP_X_FORWARDED,
+			 * HTTP_X_CLUSTER_CLIENT_IP, HTTP_FORWARDED_FOR, HTTP_FORWARDED, REMOTE_ADDR
+			 */
 			array(
-				// 'HTTP_CLIENT_IP',
 				'HTTP_X_REAL_IP',
 				'HTTP_X_FORWARDED_FOR',
-				// 'HTTP_X_FORWARDED',
-				// 'HTTP_X_CLUSTER_CLIENT_IP',
-				// 'HTTP_FORWARDED_FOR',
-				// 'HTTP_FORWARDED',
 				'REMOTE_ADDR',
 			) as $k
 		) {
@@ -303,18 +305,19 @@ class StatifyBlacklist {
 				$mask = 128;
 			}
 
-			$bytesAddr = unpack( 'n*', inet_pton( $base ) );
-			$bytesTest = unpack( 'n*', inet_pton( $ip ) );
+			$bytes_addr = unpack( 'n*', inet_pton( $base ) );
+			$bytes_est = unpack( 'n*', inet_pton( $ip ) );
 
-			if ( ! $bytesAddr || ! $bytesTest ) {
+			if ( ! $bytes_addr || ! $bytes_est ) {
 				return false;
 			}
 
-			for ( $i = 1, $ceil = ceil( $mask / 16 ); $i <= $ceil; ++ $i ) {
+			$ceil = ceil( $mask / 16 );
+			for ( $i = 1; $i <= $ceil; ++ $i ) {
 				$left  = $mask - 16 * ( $i - 1 );
 				$left  = ( $left <= 16 ) ? $left : 16;
-				$maskB = ~( 0xffff >> $left ) & 0xffff;
-				if ( ( $bytesAddr[ $i ] & $maskB ) !== ( $bytesTest[ $i ] & $maskB ) ) {
+				$mask_b = ~( 0xffff >> $left ) & 0xffff;
+				if ( ( $bytes_addr[ $i ] & $mask_b ) !== ( $bytes_est[ $i ] & $mask_b ) ) {
 					return false;
 				}
 			}
@@ -341,6 +344,6 @@ class StatifyBlacklist {
 			}
 
 			return ( 0 === substr_compare( sprintf( '%032b', ip2long( $ip ) ), sprintf( '%032b', ip2long( $base ) ), 0, $mask ) );
-		}
+		} // End if().
 	}
 }
diff --git a/phpcs.xml b/phpcs.xml
index 797a05d..410eb97 100644
--- a/phpcs.xml
+++ b/phpcs.xml
@@ -8,6 +8,7 @@
 
 		<!-- The plugin uses switch_to_blog for multisite handling. -->
 		<exclude name="WordPress.VIP.RestrictedFunctions.switch_to_blog"/>
+		<exclude name="WordPress.VIP.RestrictedFunctions.switch_to_blog_switch_to_blog"/>
 
 		<!-- Direct queries used to clean up statify table. -->
 		<exclude name="WordPress.VIP.DirectDatabaseQuery.DirectQuery"/>
diff --git a/statify-blacklist.php b/statify-blacklist.php
index 3e5c74f..156a4b4 100644
--- a/statify-blacklist.php
+++ b/statify-blacklist.php
@@ -33,7 +33,7 @@
  */
 
 // Quit.
-defined( 'ABSPATH' ) or exit;
+defined( 'ABSPATH' ) || exit;
 
 // Constants.
 define( 'STATIFYBLACKLIST_FILE', __FILE__ );
@@ -67,10 +67,10 @@ function statify_blacklist_autoload( $class ) {
 		'StatifyBlacklist_System',
 	);
 
-	if ( in_array( $class, $plugin_classes ) ) {
+	if ( in_array( $class, $plugin_classes, true ) ) {
 		require_once(
 			sprintf(
-				'%s/inc/%s.class.php',
+				'%s/inc/class-%s.php',
 				STATIFYBLACKLIST_DIR,
 				strtolower( str_replace( '_', '-', $class ) )
 			)
diff --git a/test/statifyblacklist-test.php b/test/statifyblacklist-test.php
index 90a666e..6b20bbb 100644
--- a/test/statifyblacklist-test.php
+++ b/test/statifyblacklist-test.php
@@ -20,17 +20,17 @@ const ABSPATH = false;
 /**
  * The StatifyBlacklist base class.
  */
-require_once( 'inc/statifyblacklist.class.php' );
+require_once( 'inc/class-statifyblacklist.php' );
 
 /**
  * The StatifyBlacklist system class.
  */
-require_once( 'inc/statifyblacklist-system.class.php' );
+require_once( 'inc/class-statifyblacklist-system.php' );
 
 /**
  * The StatifyBlacklist admin class.
  */
-require_once( 'inc/statifyblacklist-admin.class.php' );
+require_once( 'inc/class-statifyblacklist-admin.php' );
 
 /**
  * Class StatifyBlacklistTest.
diff --git a/views/settings-page.php b/views/settings-page.php
index c9919df..c7ffbd0 100755
--- a/views/settings-page.php
+++ b/views/settings-page.php
@@ -10,7 +10,7 @@
  */
 
 // Quit.
-defined( 'ABSPATH' ) or exit;
+defined( 'ABSPATH' ) || exit;
 
 // Update plugin options.
 if ( ! empty( $_POST['statifyblacklist'] ) ) {
@@ -48,7 +48,7 @@ if ( ! empty( $_POST['statifyblacklist'] ) ) {
 		}
 
 		// Update options (data will be sanitized).
-		$statifyBlacklistUpdateResult = StatifyBlacklist_Admin::update_options(
+		$statifyblacklist_update_result = StatifyBlacklist_Admin::update_options(
 			array(
 				'referer' => array(
 					'active'    => (int) $_POST['statifyblacklist']['referer']['active'],
@@ -71,17 +71,18 @@ if ( ! empty( $_POST['statifyblacklist'] ) ) {
 		);
 
 		// Generate messages.
-		if ( false !== $statifyBlacklistUpdateResult ) {
-			if ( array_key_exists( 'referer', $statifyBlacklistUpdateResult ) ) {
-				$statifyBlacklistPostWarning = __( 'Some URLs are invalid and have been sanitized.', 'statify-blacklist' );
-			} elseif ( array_key_exists( 'ip', $statifyBlacklistUpdateResult ) ) {
-				$statifyBlacklistPostWarning = sprintf( __( 'Some IPs are invalid : %s', 'statify-blacklist' ), implode( ', ', $statifyBlacklistUpdateResult['ip'] ) );
+		if ( false !== $statifyblacklist_update_result ) {
+			if ( array_key_exists( 'referer', $statifyblacklist_update_result ) ) {
+				$statifyblacklist_post_warning = __( 'Some URLs are invalid and have been sanitized.', 'statify-blacklist' );
+			} elseif ( array_key_exists( 'ip', $statifyblacklist_update_result ) ) {
+				// translators: List of invalid IP addresses (comma separated).
+				$statifyblacklist_post_warning = sprintf( __( 'Some IPs are invalid : %s', 'statify-blacklist' ), implode( ', ', $statifyblacklist_update_result['ip'] ) );
 			}
 		} else {
-			$statifyBlacklistPostSuccess = __( 'Settings updated successfully.', 'statify-blacklist' );
+			$statifyblacklist_post_success = __( 'Settings updated successfully.', 'statify-blacklist' );
 		}
-	}
-}
+	} // End if().
+} // End if().
 ?>
 
 <div class="wrap">
@@ -92,16 +93,16 @@ if ( ! empty( $_POST['statifyblacklist'] ) ) {
 		esc_html( 'Statify plugin is not active.' );
 		print '</p></div>';
 	}
-	if ( isset( $statifyBlacklistPostWarning ) ) {
+	if ( isset( $statifyblacklist_post_warning ) ) {
 		print '<div class="notice notice-warning"><p>' .
-			esc_html( $statifyBlacklistPostWarning );
+			esc_html( $statifyblacklist_post_warning );
 		print '<br/>';
 		esc_html_e( 'Settings have not been saved yet.', 'statify-blacklist' );
 		print '</p></div>';
 	}
-	if ( isset( $statifyBlacklistPostSuccess ) ) {
+	if ( isset( $statifyblacklist_post_success ) ) {
 		print '<div class="notice notice-success"><p>' .
-			esc_html( $statifyBlacklistPostSuccess ) .
+			esc_html( $statifyblacklist_post_success ) .
 			'</p></div>';
 	}
 	?>
@@ -152,8 +153,8 @@ if ( ! empty( $_POST['statifyblacklist'] ) ) {
 					<label for="statify-blacklist_referer">
 						<?php esc_html_e( 'Referer blacklist', 'statify-blacklist' ); ?>:<br />
 						<textarea cols="40" rows="5" name="statifyblacklist[referer][blacklist]" id="statify-blacklist_referer"><?php
-						if ( isset( $statifyBlacklistUpdateResult['referer'] ) ) {
-							print esc_html( implode( "\r\n", array_keys( $statifyBlacklistUpdateResult['referer'] ) ) );
+						if ( isset( $statifyblacklist_update_result['referer'] ) ) {
+							print esc_html( implode( "\r\n", array_keys( $statifyblacklist_update_result['referer'] ) ) );
 						} else {
 							print esc_html( implode( "\r\n", array_keys( StatifyBlacklist::$_options['referer']['blacklist'] ) ) );
 						}
@@ -214,8 +215,8 @@ if ( ! empty( $_POST['statifyblacklist'] ) ) {
 					<label for="statify-blacklist_target">
 						<?php esc_html_e( 'Target blacklist', 'statify-blacklist' ); ?>:<br />
 						<textarea cols="40" rows="5" name="statifyblacklist[target][blacklist]" id="statify-blacklist_target"><?php
-						if ( isset( $statifyBlacklistUpdateResult['target'] ) ) {
-							print esc_html( implode( "\r\n", array_keys( $statifyBlacklistUpdateResult['target'] ) ) );
+						if ( isset( $statifyblacklist_update_result['target'] ) ) {
+							print esc_html( implode( "\r\n", array_keys( $statifyblacklist_update_result['target'] ) ) );
 						} else {
 							print esc_html( implode( "\r\n", array_keys( StatifyBlacklist::$_options['target']['blacklist'] ) ) );
 						}
@@ -251,7 +252,7 @@ if ( ! empty( $_POST['statifyblacklist'] ) ) {
 					<label for="statify-blacklist_ip">
 						<?php esc_html_e( 'IP blacklist', 'statify-blacklist' ); ?>:<br />
 						<textarea cols="40" rows="5" name="statifyblacklist[ip][blacklist]" id="statify-blacklist_ip"><?php
-						if ( isset( $statifyBlacklistUpdateResult['ip'] ) ) {
+						if ( isset( $statifyblacklist_update_result['ip'] ) ) {
 							print esc_html( $_POST['statifyblacklist']['ip']['blacklist'] );
 						} else {
 							print esc_html( implode( "\r\n", StatifyBlacklist::$_options['ip']['blacklist'] ) );