diff --git a/src/AbstractFilter.php b/src/AbstractFilter.php
index 097e0c0..e596976 100644
--- a/src/AbstractFilter.php
+++ b/src/AbstractFilter.php
@@ -65,6 +65,14 @@ protected function setTarget( $target )
         $this->target = $target;
     }
 
+    /**
+     * Destroy the singleton
+     */
+    public static function destroyInstance()
+    {
+        static::$_INSTANCE = null;
+    }
+
     /**
      * @param string              $source
      * @param string              $target
diff --git a/src/Filters/Snails.php b/src/Filters/Snails.php
new file mode 100644
index 0000000..edcee94
--- /dev/null
+++ b/src/Filters/Snails.php
@@ -0,0 +1,31 @@
+<?php
+
+namespace Matecat\SubFiltering\Filters;
+
+use Matecat\SubFiltering\Commons\AbstractHandler;
+use Matecat\SubFiltering\Commons\Constants;
+
+class Snails extends AbstractHandler
+{
+    /**
+     * @inheritDoc
+     */
+    public function transform( $segment )
+    {
+        preg_match_all( '/@@[^<>\s]+?@@|@[^<>\s@]+?@/', $segment, $html, PREG_SET_ORDER );
+        foreach ( $html as $pos => $snail_variable ) {
+            //check if inside twig variable there is a tag because in this case shouldn't replace the content with PH tag
+            if( !strstr($snail_variable[0], Constants::GTPLACEHOLDER) ){
+                //replace subsequent elements excluding already encoded
+                $segment = preg_replace(
+                        '/' . preg_quote( $snail_variable[0], '/' ) . '/',
+                        '<ph id="__mtc_' . $this->getPipeline()->getNextId() . '" equiv-text="base64:' . base64_encode( $snail_variable[ 0 ] ) . '"/>',
+                        $segment,
+                        1
+                );
+            }
+        }
+
+        return $segment;
+    }
+}
\ No newline at end of file
diff --git a/src/MyMemoryFilter.php b/src/MyMemoryFilter.php
index 3f6cf9c..ce0ede0 100644
--- a/src/MyMemoryFilter.php
+++ b/src/MyMemoryFilter.php
@@ -2,6 +2,7 @@
 
 namespace Matecat\SubFiltering;
 
+
 use Matecat\SubFiltering\Commons\Pipeline;
 use Matecat\SubFiltering\Filters\CtrlCharsPlaceHoldToAscii;
 use Matecat\SubFiltering\Filters\EncodeToRawXML;
@@ -25,6 +26,8 @@
 use Matecat\SubFiltering\Filters\SubFilteredPhToHtml;
 use Matecat\SubFiltering\Filters\TwigToPh;
 use Matecat\SubFiltering\Filters\Variables;
+use Matecat\SubFiltering\Filters\Snails;
+use Matecat\SubFiltering\Filters\DoubleSnail;
 
 /**
  * Class MyMemoryFilter
@@ -39,6 +42,7 @@
  * @package Matecat\SubFiltering
  */
 class MyMemoryFilter extends AbstractFilter {
+
     /**
      * Used to transform database raw xml content ( Layer 0 ) to the sub filtered structures, used for server to server ( Ex: TM/MT ) communications ( Layer 1 )
      *
@@ -47,14 +51,15 @@ class MyMemoryFilter extends AbstractFilter {
      *
      * @return mixed
      */
-    public function fromLayer0ToLayer1( $segment, $cid = null ) {
+    public function fromLayer0ToLayer1( $segment, $cid = null )
+    {
         $channel = new Pipeline( $this->source, $this->target );
         $channel->addLast( new StandardPHToMateCatCustomPH() );
         $channel->addLast( new PlaceHoldXliffTags() );
         $channel->addLast( new LtGtDecode() );
         $channel->addLast( new HtmlToPh() );
         if ( $cid == 'airbnb' ) {
-            $channel->addLast( new Variables() ); // SE AIRBNB
+            $channel->addLast( new Variables() );
             $channel->addLast( new SmartCounts() );
         }
 
@@ -67,7 +72,8 @@ public function fromLayer0ToLayer1( $segment, $cid = null ) {
             $channel->remove( new TwigToPh() );
             $channel->remove( new SprintfToPH() );
             $channel->addAfter( new HtmlToPh(), new RubyOnRailsI18n() );
-            $channel->addAfter( new RubyOnRailsI18n(), new Percentages() );
+            $channel->addAfter( new RubyOnRailsI18n(), new Snails() );
+            $channel->addAfter( new Snails(), new Percentages() );
             $channel->addAfter( new Percentages(), new SprintfToPH() );
             $channel->addAfter( new SprintfToPH(), new TwigToPh() );
             $channel->addAfter( new TwigToPh(), new SingleCurlyBracketsToPh() );
diff --git a/tests/MateCatSubFilteringTest.php b/tests/MateCatSubFilteringTest.php
index 8aba6ec..3b26b5d 100644
--- a/tests/MateCatSubFilteringTest.php
+++ b/tests/MateCatSubFilteringTest.php
@@ -12,12 +12,16 @@
 use Matecat\SubFiltering\Utils\CatUtils;
 use PHPUnit\Framework\TestCase;
 
-class MateCatSubFilteringTest extends TestCase {
+class MateCatSubFilteringTest extends TestCase
+{
     /**
      * @return \Matecat\SubFiltering\AbstractFilter
      * @throws \Exception
      */
-    private function getFilterInstance() {
+    private function getFilterInstance()
+    {
+        MateCatFilter::destroyInstance(); // for isolation test
+
         return MateCatFilter::getInstance( new FeatureSet(), 'en-US', 'it-IT' );
     }
 
diff --git a/tests/MyMemorySubFilteringTest.php b/tests/MyMemorySubFilteringTest.php
index 5639c8d..e4c839c 100644
--- a/tests/MyMemorySubFilteringTest.php
+++ b/tests/MyMemorySubFilteringTest.php
@@ -3,7 +3,6 @@
 namespace Matecat\SubFiltering\Tests;
 
 use Matecat\SubFiltering\MyMemoryFilter;
-use Matecat\SubFiltering\Tests\Mocks\Features\AirbnbFeature;
 use Matecat\SubFiltering\Tests\Mocks\FeatureSet;
 use PHPUnit\Framework\TestCase;
 
@@ -15,11 +14,16 @@ class MyMemorySubFilteringTest extends TestCase
      */
     private function getFilterInstance()
     {
-        $featureSet = new FeatureSet([new AirbnbFeature()]);
+        MyMemoryFilter::destroyInstance(); // for isolation test
 
-        return MyMemoryFilter::getInstance($featureSet, 'en-US','it-IT', []);
+        return MyMemoryFilter::getInstance(new FeatureSet(), 'en-US','it-IT', []);
     }
 
+    /**
+     * Test for Airbnb
+     *
+     * @throws \Exception
+     */
     public function testVariablesWithHTML()
     {
         $filter = $this->getFilterInstance();
@@ -28,6 +32,54 @@ public function testVariablesWithHTML()
         $segment_from_UI = 'Airbnb account.<ph id="mtc_1" equiv-text="base64:JXtcbn0="/>%{<ph id="mtc_2" equiv-text="base64:Jmx0O2JyJmd0Ow=="/>}<ph id="mtc_3" equiv-text="base64:JXtcbn0="/>1) From ';
 
         $this->assertEquals( $db_segment, $filter->fromLayer1ToLayer0( $segment_from_UI ) );
-        $this->assertEquals( $segment_from_UI, $filter->fromLayer0ToLayer1( $db_segment ) );
+        $this->assertEquals( $segment_from_UI, $filter->fromLayer0ToLayer1( $db_segment, 'airbnb' ) );
+    }
+
+    /**
+     * Test for skyscanner
+     *
+     * @throws \Exception
+     */
+    public function testSingleSnailSyntax()
+    {
+        $filter = $this->getFilterInstance();
+
+        $db_segment      = 'This syntax @this is a variable@ is not valid';
+        $segment_from_UI = 'This syntax @this is a variable@ is not valid';
+
+        $this->assertEquals( $db_segment, $filter->fromLayer1ToLayer0( $segment_from_UI ) );
+        $this->assertEquals( $segment_from_UI, $filter->fromLayer0ToLayer1( $db_segment, 'skyscanner' ) );
+
+        $filter = $this->getFilterInstance();
+
+        $db_segment      = 'This syntax @this_is_a_variable@ is valid';
+        $segment_from_UI = 'This syntax <ph id="mtc_1" equiv-text="base64:QHRoaXNfaXNfYV92YXJpYWJsZUA="/> is valid';
+
+        $this->assertEquals( $db_segment, $filter->fromLayer1ToLayer0( $segment_from_UI ) );
+        $this->assertEquals( $segment_from_UI, $filter->fromLayer0ToLayer1( $db_segment, 'skyscanner' ) );
+    }
+
+    /**
+     * Test for skyscanner
+     *
+     * @throws \Exception
+     */
+    public function testDoubleSnailSyntax()
+    {
+        $filter = $this->getFilterInstance();
+
+        $db_segment      = 'This syntax @@this is a variable@@ is not valid';
+        $segment_from_UI = 'This syntax @@this is a variable@@ is not valid';
+
+        $this->assertEquals( $db_segment, $filter->fromLayer1ToLayer0( $segment_from_UI ) );
+        $this->assertEquals( $segment_from_UI, $filter->fromLayer0ToLayer1( $db_segment, 'skyscanner' ) );
+
+        $filter = $this->getFilterInstance();
+
+        $db_segment      = 'This syntax @@this_is_a_variable@@ is valid';
+        $segment_from_UI = 'This syntax <ph id="mtc_1" equiv-text="base64:QEB0aGlzX2lzX2FfdmFyaWFibGVAQA=="/> is valid';
+
+        $this->assertEquals( $db_segment, $filter->fromLayer1ToLayer0( $segment_from_UI ) );
+        $this->assertEquals( $segment_from_UI, $filter->fromLayer0ToLayer1( $db_segment, 'skyscanner' ) );
     }
 }
\ No newline at end of file
diff --git a/tests/TestHandlersOrder.php b/tests/TestHandlersOrder.php
index e5583a4..599bcc5 100644
--- a/tests/TestHandlersOrder.php
+++ b/tests/TestHandlersOrder.php
@@ -54,7 +54,7 @@ public function testReOrder() {
         $this->channel->addAfter( new SprintfToPH(), new TwigToPh() );
         $this->channel->addAfter( new TwigToPh(), new SingleCurlyBracketsToPh() );
 
-        $reflection = new ReflectionClass( $this->channel );
+        $reflection = new \ReflectionClass( $this->channel );
         $property   = $reflection->getProperty( 'handlers' );
         $property->setAccessible( true );
         $handlersList = $property->getValue( $this->channel );