diff --git a/Models/AttributeHolderTrait.php b/Models/AttributeHolderTrait.php
index 323b1c1..a0a4913 100755
--- a/Models/AttributeHolderTrait.php
+++ b/Models/AttributeHolderTrait.php
@@ -79,6 +79,15 @@ trait AttributeHolderTrait
         return false;
     }
 
+    /**
+     * Check if a certain attribute type exists by name
+     *
+     * @param string $attrName Attribute name to check
+     *
+     * @return bool
+     *
+     * @since 1.0.0
+     */
     public function hasAttributeType(string $attrName) : bool
     {
         foreach ($this->attributes as $attribute) {
diff --git a/Models/AttributeValue.php b/Models/AttributeValue.php
index dd3d12b..9835c11 100755
--- a/Models/AttributeValue.php
+++ b/Models/AttributeValue.php
@@ -104,9 +104,9 @@ class AttributeValue implements \JsonSerializable
     /**
      * Localization
      *
-     * @var null|BaseStringL11n
+     * @var string|BaseStringL11n
      */
-    public ?BaseStringL11n $l11n = null;
+    public string | BaseStringL11n $l11n = '';
 
     /**
      * Set l11n
diff --git a/Models/PermissionCategory.php b/Models/PermissionCategory.php
index d32475a..9c3fd04 100755
--- a/Models/PermissionCategory.php
+++ b/Models/PermissionCategory.php
@@ -17,7 +17,7 @@ namespace Modules\Attribute\Models;
 use phpOMS\Stdlib\Base\Enum;
 
 /**
- * Permision state enum.
+ * Permission category enum.
  *
  * @package Modules\Attribute\Models
  * @license OMS License 2.0
diff --git a/Theme/Backend/Components/attributes.tpl.php b/Theme/Backend/Components/attributes.tpl.php
index b5b87eb..d80cae8 100644
--- a/Theme/Backend/Components/attributes.tpl.php
+++ b/Theme/Backend/Components/attributes.tpl.php
@@ -33,7 +33,7 @@ $l11n = $this->data['defaultlocalization'] ?? new NullLocalization();
             data-add-tpl="#attributeTable tbody .oms-add-tpl-attribute">
             <div class="portlet-head"><?= $this->getHtml('Attribute', 'Attribute', 'Backend'); ?></div>
             <div class="portlet-body">
-                <input type="hidden" id="iAttributeRef" name="ref" value="<?= $this->refId ?>" disabled>
+                <input type="hidden" id="iAttributeRef" name="ref" value="<?= $this->refId; ?>" disabled>
 
                 <div class="form-group">
                     <label for="iAttributeId"><?= $this->getHtml('ID', '0', '0'); ?></label>
@@ -81,7 +81,7 @@ $l11n = $this->data['defaultlocalization'] ?? new NullLocalization();
     <section class="portlet">
         <div class="portlet-head"><?= $this->getHtml('Attributes', 'Attribute', 'Backend'); ?><i class="g-icon download btn end-xs">download</i></div>
         <div class="slider">
-        <table id="attributeTable" class="default"
+        <table id="attributeTable" class="default sticky"
             data-tag="form"
             data-ui-element="tr"
             data-add-tpl=".oms-add-tpl-attribute"
diff --git a/tests/Models/AttributeTest.php b/tests/Models/AttributeTest.php
index c3a950a..bc069d8 100644
--- a/tests/Models/AttributeTest.php
+++ b/tests/Models/AttributeTest.php
@@ -45,7 +45,7 @@ final class AttributeTest extends \PHPUnit\Framework\TestCase
 
         self::assertEquals(
             [
-                'id' => 0,
+                'id'  => 0,
                 'ref' => 0,
             ],
             $array
@@ -63,7 +63,7 @@ final class AttributeTest extends \PHPUnit\Framework\TestCase
 
         self::assertEquals(
             [
-                'id' => 0,
+                'id'  => 0,
                 'ref' => 0,
             ],
             $array
diff --git a/tests/Models/AttributeTypeTest.php b/tests/Models/AttributeTypeTest.php
index d766022..288624b 100644
--- a/tests/Models/AttributeTypeTest.php
+++ b/tests/Models/AttributeTypeTest.php
@@ -27,7 +27,7 @@ final class AttributeTypeTest extends \PHPUnit\Framework\TestCase
 {
     public function testGetDefaultString() : void
     {
-        $type = new AttributeType();
+        $type             = new AttributeType();
         $type->defaults[] = new AttributeValue();
         $type->defaults[0]->setValue('abc', AttributeValueType::_STRING);
 
@@ -36,7 +36,7 @@ final class AttributeTypeTest extends \PHPUnit\Framework\TestCase
 
     public function testGetDefaultInt() : void
     {
-        $type = new AttributeType();
+        $type             = new AttributeType();
         $type->defaults[] = new AttributeValue();
         $type->defaults[0]->setValue(1, AttributeValueType::_INT);
 
@@ -45,7 +45,7 @@ final class AttributeTypeTest extends \PHPUnit\Framework\TestCase
 
     public function testGetDefaultFloatInt() : void
     {
-        $type = new AttributeType();
+        $type             = new AttributeType();
         $type->defaults[] = new AttributeValue();
         $type->defaults[0]->setValue(1, AttributeValueType::_FLOAT_INT);
 
@@ -54,16 +54,16 @@ final class AttributeTypeTest extends \PHPUnit\Framework\TestCase
 
     public function testGetDefaultBool() : void
     {
-        $type = new AttributeType();
+        $type             = new AttributeType();
         $type->defaults[] = new AttributeValue();
         $type->defaults[0]->setValue(false, AttributeValueType::_BOOL);
 
-        self::assertEquals(false, $type->getDefaultByValue(false)->getValue());
+        self::assertFalse($type->getDefaultByValue(false)->getValue());
     }
 
     public function testGetDefaultFloat() : void
     {
-        $type = new AttributeType();
+        $type             = new AttributeType();
         $type->defaults[] = new AttributeValue();
         $type->defaults[0]->setValue(1.23, AttributeValueType::_FLOAT);
 
@@ -72,7 +72,7 @@ final class AttributeTypeTest extends \PHPUnit\Framework\TestCase
 
     public function testGetDefaultDateTime() : void
     {
-        $type = new AttributeType();
+        $type             = new AttributeType();
         $type->defaults[] = new AttributeValue();
         $type->defaults[0]->setValue($val = new \DateTime('now'), AttributeValueType::_DATETIME);
 
@@ -81,7 +81,7 @@ final class AttributeTypeTest extends \PHPUnit\Framework\TestCase
 
     public function testDefaultId() : void
     {
-        $type = new AttributeType();
+        $type             = new AttributeType();
         $type->defaults[] = new AttributeValue();
 
         self::assertTrue($type->hasDefaultId(0));
@@ -94,11 +94,11 @@ final class AttributeTypeTest extends \PHPUnit\Framework\TestCase
 
         self::assertEquals(
             [
-                'id' => 0,
-                'name' => '',
+                'id'                => 0,
+                'name'              => '',
                 'validationPattern' => '',
-                'custom' => false,
-                'isRequired' => false,
+                'custom'            => false,
+                'isRequired'        => false,
             ],
             $type->toArray()
         );
@@ -110,11 +110,11 @@ final class AttributeTypeTest extends \PHPUnit\Framework\TestCase
 
         self::assertEquals(
             [
-                'id' => 0,
-                'name' => '',
+                'id'                => 0,
+                'name'              => '',
                 'validationPattern' => '',
-                'custom' => false,
-                'isRequired' => false,
+                'custom'            => false,
+                'isRequired'        => false,
             ],
             $type->jsonSerialize()
         );
diff --git a/tests/Models/AttributeValueTest.php b/tests/Models/AttributeValueTest.php
index a4a33ff..02965aa 100644
--- a/tests/Models/AttributeValueTest.php
+++ b/tests/Models/AttributeValueTest.php
@@ -16,7 +16,6 @@ namespace Modules\Admin\tests\Models;
 
 use Modules\Attribute\Models\AttributeValue;
 use Modules\Attribute\Models\AttributeValueType;
-use Modules\Attribute\Models\AttributeValueValue;
 
 /**
  * @testdox Modules\Admin\tests\Models\AttributeValueTest: Attribute model
@@ -54,7 +53,7 @@ final class AttributeValueTest extends \PHPUnit\Framework\TestCase
         $value = new AttributeValue();
         $value->setValue(false, AttributeValueType::_BOOL);
 
-        self::assertEquals(false, $value->getValue());
+        self::assertFalse($value->getValue());
     }
 
     public function testGetDefaultFloat() : void
@@ -78,11 +77,11 @@ final class AttributeValueTest extends \PHPUnit\Framework\TestCase
         $value = new AttributeValue();
         self::assertEquals(
             [
-                'id' => 0,
-                'name' => '',
+                'id'                => 0,
+                'name'              => '',
                 'validationPattern' => '',
-                'custom' => false,
-                'isRequired' => false,
+                'custom'            => false,
+                'isRequired'        => false,
             ],
             $value->toArray()
         );
@@ -93,11 +92,11 @@ final class AttributeValueTest extends \PHPUnit\Framework\TestCase
         $value = new AttributeValue();
         self::assertEquals(
             [
-                'id' => 0,
-                'name' => '',
+                'id'                => 0,
+                'name'              => '',
                 'validationPattern' => '',
-                'custom' => false,
-                'isRequired' => false,
+                'custom'            => false,
+                'isRequired'        => false,
             ],
             $value->jsonSerialize()
         );