diff --git a/README.md b/README.md
index ed64d7b..f6e3655 100644
--- a/README.md
+++ b/README.md
@@ -11,7 +11,8 @@ A blacklist extension for the famous [Statify](https://wordpress.org/plugins/sta
 
 This plugin adds customizable blacklist to Statify to allow blocking of referer spam or internal interactions.
 
-### Current Features ##
+### Features ##
+
 #### Referer Blacklist ####
 Add a list of domains (for simplicity only second-level, e.g. _example.com_ which blocks _everything.example.com_).
 
@@ -80,6 +81,10 @@ Because of this, an IP blacklist can only be applied while processing the reques
 
 ## Changelog ##
 
+### Work in Progress ###
+* Relicensed to GPLv2 or later
+* Minor changes for WP Coding Standard
+
 ### 1.4.0 / 10.06.2017 ###
 * IP blacklist implemented (#7)
 * Target page blacklist implemented (#8)
diff --git a/inc/statifyblacklist.class.php b/inc/statifyblacklist.class.php
index 3b981ab..c66ca84 100644
--- a/inc/statifyblacklist.class.php
+++ b/inc/statifyblacklist.class.php
@@ -69,7 +69,7 @@ class StatifyBlacklist {
 		self::$multisite = ( is_multisite() && array_key_exists( STATIFYBLACKLIST_BASE, (array) get_site_option( 'active_sitewide_plugins' ) ) );
 
 		// Add Filter to statify hook if enabled.
-		if ( self::$_options['referer']['active'] != 0 ) {
+		if ( 0 !== self::$_options['referer']['active'] ) {
 			add_filter( 'statify__skip_tracking', array( 'StatifyBlacklist', 'apply_blacklist_filter' ) );
 		}
 
@@ -99,7 +99,7 @@ class StatifyBlacklist {
 
 		// CronJob to clean up database.
 		if ( defined( 'DOING_CRON' ) && DOING_CRON ) {
-			if ( self::$_options['referer']['cron'] == 1 || self::$_options['target']['cron'] == 1 ) {
+			if ( 1 === self::$_options['referer']['cron'] || 1 === self::$_options['target']['cron'] ) {
 				add_action( 'statify_cleanup', array( 'StatifyBlacklist_Admin', 'cleanup_database' ) );
 			}
 		}
@@ -111,7 +111,7 @@ class StatifyBlacklist {
 	 * @since 1.0.0
 	 * @since 1.2.1 update_options($options = null) Parameter with default value introduced.
 	 *
-	 * @param array $options New options to save.
+	 * @param array $options Optional. New options to save.
 	 *
 	 */
 	public static function update_options( $options = null ) {
@@ -159,20 +159,20 @@ class StatifyBlacklist {
 	 */
 	public static function apply_blacklist_filter() {
 		// Referer blacklist.
-		if ( isset( self::$_options['referer']['active'] ) && self::$_options['referer']['active'] != 0 ) {
+		if ( isset( self::$_options['referer']['active'] ) && 0 !== self::$_options['referer']['active'] ) {
 			// Regular Expression filtering since 1.3.0.
 			if ( isset( self::$_options['referer']['regexp'] ) && self::$_options['referer']['regexp'] > 0 ) {
 				// Get full referer string.
 				$referer = ( isset( $_SERVER['HTTP_REFERER'] ) ? $_SERVER['HTTP_REFERER'] : '' );
 				// Merge given regular expressions into one.
 				$regexp = '/' . implode( "|", array_keys( self::$_options['referer']['blacklist'] ) ) . '/';
-				if ( self::$_options['referer']['regexp'] == 2 ) {
+				if ( 2 === self::$_options['referer']['regexp'] ) {
 					$regexp .= 'i';
 				}
 
 				// Check blacklist (return NULL to continue filtering).
 
-				return ( preg_match( $regexp, $referer ) === 1 ) ? true : null;
+				return ( 1 === preg_match( $regexp, $referer ) ) ? true : null;
 			} else {
 				// Extract relevant domain parts.
 				$referer = strtolower( ( isset( $_SERVER['HTTP_REFERER'] ) ? parse_url( $_SERVER['HTTP_REFERER'], PHP_URL_HOST ) : '' ) );
@@ -188,20 +188,20 @@ class StatifyBlacklist {
 		}
 
 		// Target blacklist (since 1.4.0)
-		if ( isset( self::$_options['target']['active'] ) && self::$_options['target']['active'] != 0 ) {
+		if ( isset( self::$_options['target']['active'] ) && 0 !== self::$_options['target']['active'] ) {
 			// Regular Expression filtering since 1.3.0.
-			if ( isset( self::$_options['target']['regexp'] ) && self::$_options['target']['regexp'] > 0 ) {
+			if ( isset( self::$_options['target']['regexp'] ) && 0 < self::$_options['target']['regexp'] ) {
 				// Get full referer string.
 				$target = ( isset( $_SERVER['REQUEST_URI'] ) ? wp_unslash( $_SERVER['REQUEST_URI'] ) : '/' );
 				// Merge given regular expressions into one
 				$regexp = '/' . implode( "|", array_keys( self::$_options['target']['blacklist'] ) ) . '/';
-				if ( self::$_options['target']['regexp'] == 2 ) {
+				if ( 2 === self::$_options['target']['regexp'] ) {
 					$regexp .= 'i';
 				}
 
 				// Check blacklist (return NULL to continue filtering).
 
-				return ( preg_match( $regexp, $target ) === 1 ) ? true : null;
+				return ( 1 === preg_match( $regexp, $target ) ) ? true : null;
 			} else {
 				// Extract target page.
 				$target = ( isset( $_SERVER['REQUEST_URI'] ) ? wp_unslash( $_SERVER['REQUEST_URI'] ) : '/' );
@@ -215,8 +215,8 @@ class StatifyBlacklist {
 		}
 
 		// IP blacklist (since 1.4.0).
-		if ( isset ( self::$_options['ip']['active'] ) && self::$_options['ip']['active'] != 0 ) {
-			if ( ( $ip = self::getIP() ) !== false ) {
+		if ( isset ( self::$_options['ip']['active'] ) && 0 !== self::$_options['ip']['active'] ) {
+			if ( false !== ( $ip = self::getIP() ) ) {
 				foreach ( self::$_options['ip']['blacklist'] as $net ) {
 					if ( self::cidrMatch( $ip, $net ) ) {
 						return true;
@@ -254,7 +254,7 @@ class StatifyBlacklist {
 		) {
 			if ( isset( $_SERVER[$k] ) ) {
 				foreach ( explode( ',', $_SERVER[$k] ) as $ip ) {
-					if ( filter_var( $ip, FILTER_VALIDATE_IP ) !== false ) {
+					if ( false !== filter_var( $ip, FILTER_VALIDATE_IP ) ) {
 						return $ip;
 					}
 				}
@@ -300,7 +300,7 @@ class StatifyBlacklist {
 				$left  = $mask - 16 * ( $i - 1 );
 				$left  = ( $left <= 16 ) ? $left : 16;
 				$maskB = ~( 0xffff >> $left ) & 0xffff;
-				if ( ( $bytesAddr[$i] & $maskB ) != ( $bytesTest[$i] & $maskB ) ) {
+				if ( ( $bytesAddr[$i] & $maskB ) !== ( $bytesTest[$i] & $maskB ) ) {
 					return false;
 				}
 			}
@@ -326,7 +326,7 @@ class StatifyBlacklist {
 				$mask = 32;
 			}
 
-			return 0 === substr_compare( sprintf( '%032b', ip2long( $ip ) ), sprintf( '%032b', ip2long( $base ) ), 0, $mask );
+			return ( 0 === substr_compare( sprintf( '%032b', ip2long( $ip ) ), sprintf( '%032b', ip2long( $base ) ), 0, $mask ) );
 		}
 	}
 }
diff --git a/inc/statifyblacklist_admin.class.php b/inc/statifyblacklist_admin.class.php
index cc9b74a..f13d006 100644
--- a/inc/statifyblacklist_admin.class.php
+++ b/inc/statifyblacklist_admin.class.php
@@ -21,7 +21,7 @@ class StatifyBlacklist_Admin extends StatifyBlacklist {
 	/**
 	 * Update options.
 	 *
-	 * @param  array $options New options to save.
+	 * @param  array $options Optional. New options to save.
 	 *
 	 * @return array|bool  array of sanitized array on errors, FALSE if there were none.
 	 * @since 1.1.1
@@ -30,7 +30,7 @@ class StatifyBlacklist_Admin extends StatifyBlacklist {
 		if ( isset( $options ) && current_user_can( 'manage_options' ) ) {
 			// Sanitize URLs and remove empty inputs.
 			$givenReferer = $options['referer']['blacklist'];
-			if ( $options['referer']['regexp'] == 0 ) {
+			if ( 0 === $options['referer']['regexp'] ) {
 				$sanitizedReferer = self::sanitizeURLs( $givenReferer );
 			} else {
 				$sanitizedReferer = $givenReferer;
@@ -107,7 +107,7 @@ class StatifyBlacklist_Admin extends StatifyBlacklist {
 	 *
 	 */
 	public static function plugin_meta_link( $links, $file ) {
-		if ( $file == STATIFYBLACKLIST_BASE ) {
+		if ( $file === STATIFYBLACKLIST_BASE ) {
 			$links[] = '<a href="https://github.com/stklcode/statify-blacklist">GitHub</a>';
 		}
 
@@ -128,7 +128,7 @@ class StatifyBlacklist_Admin extends StatifyBlacklist {
 	public static function plugin_actions_links( $links, $file ) {
 		$base = self::$multisite ? network_admin_url( 'settings.php' ) : admin_url( 'options-general.php' );
 
-		if ( $file == STATIFYBLACKLIST_BASE && current_user_can( 'manage_options' ) ) {
+		if ( $file === STATIFYBLACKLIST_BASE && current_user_can( 'manage_options' ) ) {
 			array_unshift(
 				$links,
 				sprintf( '<a href="%s">%s</a>', esc_attr( add_query_arg( 'page', 'statify-blacklist', $base ) ), __( 'Settings' ) )
@@ -152,8 +152,8 @@ class StatifyBlacklist_Admin extends StatifyBlacklist {
 		}
 
 		if ( defined( 'DOING_CRON' ) && DOING_CRON ) {
-			$cleanRef = ( self::$_options['referer']['cron'] == 1 );
-			$cleanTrg = ( self::$_options['target']['cron'] == 1 );
+			$cleanRef = ( 1 === self::$_options['referer']['cron'] );
+			$cleanTrg = ( 1 === self::$_options['target']['cron'] );
 		} else {
 			$cleanRef = true;
 			$cleanTrg = true;
@@ -192,7 +192,7 @@ class StatifyBlacklist_Admin extends StatifyBlacklist {
 				$wpdb->query(
 					$wpdb->prepare(
 						"DELETE FROM `$wpdb->statify` WHERE "
-						. ( ( self::$_options['referer']['regexp'] == 1 ) ? " BINARY " : "" )
+						. ( ( 1 === self::$_options['referer']['regexp'] ) ? " BINARY " : "" )
 						. "referrer REGEXP %s", $refererRegexp
 					)
 				);
@@ -201,7 +201,7 @@ class StatifyBlacklist_Admin extends StatifyBlacklist {
 				$wpdb->query(
 					$wpdb->prepare(
 						"DELETE FROM `$wpdb->statify` WHERE "
-						. ( ( self::$_options['target']['regexp'] == 1 ) ? " BINARY " : "" )
+						. ( ( 1 === self::$_options['target']['regexp'] ) ? " BINARY " : "" )
 						. "target REGEXP %s", $targetRegexp
 					)
 				);
diff --git a/inc/statifyblacklist_system.class.php b/inc/statifyblacklist_system.class.php
index 394f16d..10e3bf7 100644
--- a/inc/statifyblacklist_system.class.php
+++ b/inc/statifyblacklist_system.class.php
@@ -125,7 +125,7 @@ class StatifyBlacklist_System extends StatifyBlacklist {
 				),
 				'version' => 1.4
 			);
-			if ( ( is_multisite() && array_key_exists( STATIFYBLACKLIST_BASE, (array) get_site_option( 'active_sitewide_plugins' ) ) ) ) {
+			if ( is_multisite() && array_key_exists( STATIFYBLACKLIST_BASE, (array) get_site_option( 'active_sitewide_plugins' ) ) ) {
 				update_site_option( 'statify-blacklist', $options );
 			} else {
 				update_option( 'statify-blacklist', $options );
@@ -134,7 +134,7 @@ class StatifyBlacklist_System extends StatifyBlacklist {
 		}
 
 		// Version older than current major release.
-		if ( self::$_options['version'] < self::VERSION_MAIN ) {
+		if ( self::VERSION_MAIN > self::$_options['version'] ) {
 			// Merge default options with current config, assuming only additive changes.
 			$options            = array_merge_recursive( self::defaultOptions(), self::$_options );
 			$options['version'] = self::VERSION_MAIN;