diff --git a/src/Controller/AdminPages/BaseAdminController.php b/src/Controller/AdminPages/BaseAdminController.php
index 3e7f546c..366842eb 100644
--- a/src/Controller/AdminPages/BaseAdminController.php
+++ b/src/Controller/AdminPages/BaseAdminController.php
@@ -56,7 +56,7 @@ use App\Form\AdminPages\MassCreationForm;
 use App\Services\Attachments\AttachmentSubmitHandler;
 use App\Services\EntityExporter;
 use App\Services\EntityImporter;
-use App\Services\LabelSystem\BarcodeExampleElementsGenerator;
+use App\Services\LabelSystem\Barcodes\BarcodeExampleElementsGenerator;
 use App\Services\LabelSystem\LabelGenerator;
 use App\Services\LogSystem\EventCommentHelper;
 use App\Services\LogSystem\HistoryHelper;
diff --git a/src/Services/LabelSystem/BarcodeGenerator.php b/src/Services/LabelSystem/BarcodeGenerator.php
index 507abce6..70f68d27 100644
--- a/src/Services/LabelSystem/BarcodeGenerator.php
+++ b/src/Services/LabelSystem/BarcodeGenerator.php
@@ -24,9 +24,9 @@ use App\Entity\LabelSystem\LabelOptions;
 use App\Services\LabelSystem\Barcodes\BarcodeContentGenerator;
 use Com\Tecnick\Barcode\Barcode;
 
-class BarcodeGenerator
+final class BarcodeGenerator
 {
-    protected $barcodeContentGenerator;
+    private $barcodeContentGenerator;
 
     public function __construct(BarcodeContentGenerator $barcodeContentGenerator)
     {
diff --git a/src/Services/LabelSystem/BarcodeParser.php b/src/Services/LabelSystem/BarcodeParser.php
index ab8243c8..12fb66c8 100644
--- a/src/Services/LabelSystem/BarcodeParser.php
+++ b/src/Services/LabelSystem/BarcodeParser.php
@@ -26,10 +26,10 @@ use Doctrine\ORM\EntityManagerInterface;
 use Doctrine\ORM\EntityNotFoundException;
 use Symfony\Component\Routing\Generator\UrlGeneratorInterface;
 
-class BarcodeParser
+final class BarcodeParser
 {
-    protected $urlGenerator;
-    protected $em;
+    private $urlGenerator;
+    private $em;
 
 
     public function __construct(UrlGeneratorInterface $urlGenerator, EntityManagerInterface $entityManager)
diff --git a/src/Services/LabelSystem/Barcodes/BarcodeContentGenerator.php b/src/Services/LabelSystem/Barcodes/BarcodeContentGenerator.php
index 7645523c..83a056f0 100644
--- a/src/Services/LabelSystem/Barcodes/BarcodeContentGenerator.php
+++ b/src/Services/LabelSystem/Barcodes/BarcodeContentGenerator.php
@@ -30,9 +30,9 @@ use App\Entity\Parts\Supplier;
 use App\Exceptions\EntityNotSupportedException;
 use Symfony\Component\Routing\Generator\UrlGeneratorInterface;
 
-class BarcodeContentGenerator
+final class BarcodeContentGenerator
 {
-    protected $urlGenerator;
+    private $urlGenerator;
 
     public const PREFIX_MAP = [
         Part::class => 'P',
@@ -40,7 +40,7 @@ class BarcodeContentGenerator
         Storelocation::class => 'S'
     ];
 
-    protected const URL_MAP = [
+    private const URL_MAP = [
         Part::class => 'part',
         PartLot::class => 'lot',
         Storelocation::class => 'location',
@@ -80,7 +80,7 @@ class BarcodeContentGenerator
         return $prefix  . $id;
     }
 
-    protected function classToString(array $map, object $target): string
+    private function classToString(array $map, object $target): string
     {
         $class = get_class($target);
         if (isset($map[$class])) {
diff --git a/src/Services/LabelSystem/BarcodeExampleElementsGenerator.php b/src/Services/LabelSystem/Barcodes/BarcodeExampleElementsGenerator.php
similarity index 94%
rename from src/Services/LabelSystem/BarcodeExampleElementsGenerator.php
rename to src/Services/LabelSystem/Barcodes/BarcodeExampleElementsGenerator.php
index c78e1fb9..96644960 100644
--- a/src/Services/LabelSystem/BarcodeExampleElementsGenerator.php
+++ b/src/Services/LabelSystem/Barcodes/BarcodeExampleElementsGenerator.php
@@ -18,7 +18,7 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
 
-namespace App\Services\LabelSystem;
+namespace App\Services\LabelSystem\Barcodes;
 
 use App\Entity\Base\AbstractStructuralDBElement;
 use App\Entity\Parts\Category;
@@ -28,7 +28,7 @@ use App\Entity\Parts\Part;
 use App\Entity\Parts\PartLot;
 use App\Entity\Parts\Storelocation;
 
-class BarcodeExampleElementsGenerator
+final class BarcodeExampleElementsGenerator
 {
     public function getElement(string $type): object
     {
@@ -44,7 +44,7 @@ class BarcodeExampleElementsGenerator
         }
     }
 
-    protected function getStorelocation(): Storelocation
+    private function getStorelocation(): Storelocation
     {
         $storelocation = new Storelocation();
         $storelocation->setName('Location 1');
@@ -59,7 +59,7 @@ class BarcodeExampleElementsGenerator
         return $storelocation;
     }
 
-    protected function getStructuralData(string $class): AbstractStructuralDBElement
+    private function getStructuralData(string $class): AbstractStructuralDBElement
     {
         if (!is_a($class, AbstractStructuralDBElement::class, true)) {
            throw new \InvalidArgumentException('$class must be an child of AbstractStructuralDBElement');
diff --git a/src/Services/LabelSystem/Barcodes/BarcodeNormalizer.php b/src/Services/LabelSystem/Barcodes/BarcodeNormalizer.php
index aad138bb..2170bcaf 100644
--- a/src/Services/LabelSystem/Barcodes/BarcodeNormalizer.php
+++ b/src/Services/LabelSystem/Barcodes/BarcodeNormalizer.php
@@ -21,9 +21,9 @@
 namespace App\Services\LabelSystem\Barcodes;
 
 
-class BarcodeNormalizer
+final class BarcodeNormalizer
 {
-    protected const PREFIX_TYPE_MAP = [
+    private const PREFIX_TYPE_MAP = [
         'L' => 'lot',
         'P' => 'part',
         'S' => 'location',
diff --git a/src/Services/LabelSystem/LabelGenerator.php b/src/Services/LabelSystem/LabelGenerator.php
index e3bcf1f0..2c8aa08c 100644
--- a/src/Services/LabelSystem/LabelGenerator.php
+++ b/src/Services/LabelSystem/LabelGenerator.php
@@ -30,7 +30,7 @@ use App\Services\ElementTypeNameGenerator;
 use Dompdf\Dompdf;
 use Twig\Environment;
 
-class LabelGenerator
+final class LabelGenerator
 {
     public const CLASS_SUPPORT_MAPPING = [
         'part' => Part::class,
@@ -40,7 +40,7 @@ class LabelGenerator
 
     public const MM_TO_POINTS_FACTOR = 2.83465;
 
-    protected $labelHTMLGenerator;
+    private $labelHTMLGenerator;
 
     public function __construct(LabelHTMLGenerator $labelHTMLGenerator)
     {
diff --git a/src/Services/LabelSystem/LabelHTMLGenerator.php b/src/Services/LabelSystem/LabelHTMLGenerator.php
index 7cf91292..ef161940 100644
--- a/src/Services/LabelSystem/LabelHTMLGenerator.php
+++ b/src/Services/LabelSystem/LabelHTMLGenerator.php
@@ -32,13 +32,13 @@ use Twig\Error\SyntaxError;
 
 final class LabelHTMLGenerator
 {
-    protected $twig;
-    protected $elementTypeNameGenerator;
-    protected $replacer;
-    protected $barcodeGenerator;
-    protected $sandboxedTwigProvider;
-    protected $partdb_title;
-    protected $security;
+    private $twig;
+    private $elementTypeNameGenerator;
+    private $replacer;
+    private $barcodeGenerator;
+    private $sandboxedTwigProvider;
+    private $partdb_title;
+    private $security;
 
     public function __construct(ElementTypeNameGenerator $elementTypeNameGenerator, LabelTextReplacer $replacer, Environment $twig,
         BarcodeGenerator $barcodeGenerator, SandboxedTwigProvider $sandboxedTwigProvider, Security $security, string $partdb_title)
diff --git a/src/Services/LabelSystem/LabelProfileDropdownHelper.php b/src/Services/LabelSystem/LabelProfileDropdownHelper.php
index eb295065..21c33592 100644
--- a/src/Services/LabelSystem/LabelProfileDropdownHelper.php
+++ b/src/Services/LabelSystem/LabelProfileDropdownHelper.php
@@ -28,7 +28,7 @@ use Doctrine\ORM\EntityManagerInterface;
 use Symfony\Contracts\Cache\ItemInterface;
 use Symfony\Contracts\Cache\TagAwareCacheInterface;
 
-class LabelProfileDropdownHelper
+final class LabelProfileDropdownHelper
 {
     private $cache;
     private $entityManager;
diff --git a/src/Services/LabelSystem/LabelTextReplacer.php b/src/Services/LabelSystem/LabelTextReplacer.php
index 3ebbb0e2..abf4c401 100644
--- a/src/Services/LabelSystem/LabelTextReplacer.php
+++ b/src/Services/LabelSystem/LabelTextReplacer.php
@@ -27,9 +27,9 @@ use App\Services\LabelSystem\PlaceholderProviders\PlaceholderProviderInterface;
  * It uses the PlaceholderProviders provided by PlaceholderProviderInterface classes.
  * @package App\Services\LabelSystem
  */
-class LabelTextReplacer
+final class LabelTextReplacer
 {
-    protected $providers;
+    private $providers;
 
     public function __construct(iterable $providers)
     {
diff --git a/src/Services/LabelSystem/PlaceholderProviders/AbstractDBElementProvider.php b/src/Services/LabelSystem/PlaceholderProviders/AbstractDBElementProvider.php
index 8fb2017e..1b60dfd3 100644
--- a/src/Services/LabelSystem/PlaceholderProviders/AbstractDBElementProvider.php
+++ b/src/Services/LabelSystem/PlaceholderProviders/AbstractDBElementProvider.php
@@ -24,9 +24,9 @@ namespace App\Services\LabelSystem\PlaceholderProviders;
 use App\Entity\Base\AbstractDBElement;
 use App\Services\ElementTypeNameGenerator;
 
-class AbstractDBElementProvider implements PlaceholderProviderInterface
+final class AbstractDBElementProvider implements PlaceholderProviderInterface
 {
-    protected $elementTypeNameGenerator;
+    private $elementTypeNameGenerator;
 
     public function __construct(ElementTypeNameGenerator $elementTypeNameGenerator)
     {
diff --git a/src/Services/LabelSystem/PlaceholderProviders/GlobalProviders.php b/src/Services/LabelSystem/PlaceholderProviders/GlobalProviders.php
index d3844b75..3b6093e0 100644
--- a/src/Services/LabelSystem/PlaceholderProviders/GlobalProviders.php
+++ b/src/Services/LabelSystem/PlaceholderProviders/GlobalProviders.php
@@ -30,11 +30,11 @@ use Symfony\Component\Security\Core\Security;
  * Provides Placeholders for infos about global infos like Installation name or datetimes.
  * @package App\Services\LabelSystem\PlaceholderProviders
  */
-class GlobalProviders implements PlaceholderProviderInterface
+final class GlobalProviders implements PlaceholderProviderInterface
 {
 
-    protected $partdb_title;
-    protected $security;
+    private $partdb_title;
+    private $security;
 
     public function __construct(string $partdb_title, Security $security)
     {
diff --git a/src/Services/LabelSystem/PlaceholderProviders/NamedElementProvider.php b/src/Services/LabelSystem/PlaceholderProviders/NamedElementProvider.php
index c4861cf4..fdaf6031 100644
--- a/src/Services/LabelSystem/PlaceholderProviders/NamedElementProvider.php
+++ b/src/Services/LabelSystem/PlaceholderProviders/NamedElementProvider.php
@@ -23,7 +23,7 @@ namespace App\Services\LabelSystem\PlaceholderProviders;
 
 use App\Entity\Contracts\NamedElementInterface;
 
-class NamedElementProvider implements PlaceholderProviderInterface
+final class NamedElementProvider implements PlaceholderProviderInterface
 {
 
     /**
diff --git a/src/Services/LabelSystem/PlaceholderProviders/PartLotProvider.php b/src/Services/LabelSystem/PlaceholderProviders/PartLotProvider.php
index 4c3bd641..0635a91c 100644
--- a/src/Services/LabelSystem/PlaceholderProviders/PartLotProvider.php
+++ b/src/Services/LabelSystem/PlaceholderProviders/PartLotProvider.php
@@ -27,10 +27,10 @@ use App\Services\LabelSystem\LabelTextReplacer;
 use IntlDateFormatter;
 use Locale;
 
-class PartLotProvider implements PlaceholderProviderInterface
+final class PartLotProvider implements PlaceholderProviderInterface
 {
-    protected $labelTextReplacer;
-    protected $amountFormatter;
+    private $labelTextReplacer;
+    private $amountFormatter;
 
     public function __construct(LabelTextReplacer $labelTextReplacer, AmountFormatter $amountFormatter)
     {
diff --git a/src/Services/LabelSystem/PlaceholderProviders/PartProvider.php b/src/Services/LabelSystem/PlaceholderProviders/PartProvider.php
index e1b9d555..b6fb5e02 100644
--- a/src/Services/LabelSystem/PlaceholderProviders/PartProvider.php
+++ b/src/Services/LabelSystem/PlaceholderProviders/PartProvider.php
@@ -25,11 +25,11 @@ use App\Entity\Parts\Part;
 use App\Services\SIFormatter;
 use Symfony\Contracts\Translation\TranslatorInterface;
 
-class PartProvider implements PlaceholderProviderInterface
+final class PartProvider implements PlaceholderProviderInterface
 {
 
-    protected $siFormatter;
-    protected $translator;
+    private $siFormatter;
+    private $translator;
 
     public function __construct(SIFormatter $SIFormatter, TranslatorInterface $translator)
     {
diff --git a/src/Services/LabelSystem/PlaceholderProviders/StructuralDBElementProvider.php b/src/Services/LabelSystem/PlaceholderProviders/StructuralDBElementProvider.php
index f4fc50b8..6a643c64 100644
--- a/src/Services/LabelSystem/PlaceholderProviders/StructuralDBElementProvider.php
+++ b/src/Services/LabelSystem/PlaceholderProviders/StructuralDBElementProvider.php
@@ -24,7 +24,7 @@ namespace App\Services\LabelSystem\PlaceholderProviders;
 use App\Entity\Base\AbstractDBElement;
 use App\Entity\Base\AbstractStructuralDBElement;
 
-class StructuralDBElementProvider implements PlaceholderProviderInterface
+final class StructuralDBElementProvider implements PlaceholderProviderInterface
 {
 
     public function replace(string $placeholder, object $label_target, array $options = []): ?string
diff --git a/src/Services/LabelSystem/PlaceholderProviders/TimestampableElementProvider.php b/src/Services/LabelSystem/PlaceholderProviders/TimestampableElementProvider.php
index 5ddc0011..4cb295cb 100644
--- a/src/Services/LabelSystem/PlaceholderProviders/TimestampableElementProvider.php
+++ b/src/Services/LabelSystem/PlaceholderProviders/TimestampableElementProvider.php
@@ -24,7 +24,7 @@ use App\Entity\Contracts\TimeStampableInterface;
 use IntlDateFormatter;
 use Locale;
 
-class TimestampableElementProvider implements PlaceholderProviderInterface
+final class TimestampableElementProvider implements PlaceholderProviderInterface
 {
 
     /**
diff --git a/src/Services/LabelSystem/SandboxedTwigProvider.php b/src/Services/LabelSystem/SandboxedTwigProvider.php
index 86103ca9..630820fe 100644
--- a/src/Services/LabelSystem/SandboxedTwigProvider.php
+++ b/src/Services/LabelSystem/SandboxedTwigProvider.php
@@ -48,10 +48,10 @@ use Twig\Extra\Intl\IntlExtension;
 use Twig\Sandbox\SecurityPolicy;
 use Twig\Sandbox\SecurityPolicyInterface;
 
-class SandboxedTwigProvider
+final class SandboxedTwigProvider
 {
-    protected const ALLOWED_TAGS = ['apply', 'autoescape', 'do', 'for', 'if', 'set', 'verbatim', 'with'];
-    protected const ALLOWED_FILTERS = ['abs', 'batch', 'capitalize', 'column', 'country_name',
+    private const ALLOWED_TAGS = ['apply', 'autoescape', 'do', 'for', 'if', 'set', 'verbatim', 'with'];
+    private const ALLOWED_FILTERS = ['abs', 'batch', 'capitalize', 'column', 'country_name',
         'currency_name', 'currency_symbol', 'date', 'date_modify', 'default', 'escape', 'filter', 'first', 'format',
         'format_currency', 'format_date', 'format_datetime', 'format_number', 'format_time', 'join', 'keys',
         'language_name', 'last', 'length', 'locale_name', 'lower', 'map', 'merge', 'nl2br', 'raw', 'number_format',
@@ -60,9 +60,9 @@ class SandboxedTwigProvider
         //Part-DB specific filters:
         'moneyFormat', 'siFormat', 'amountFormat'];
 
-    protected const ALLOWED_FUNCTIONS = ['date', 'html_classes', 'max', 'min', 'random', 'range'];
+    private const ALLOWED_FUNCTIONS = ['date', 'html_classes', 'max', 'min', 'random', 'range'];
 
-    protected const ALLOWED_METHODS = [
+    private const ALLOWED_METHODS = [
         NamedElementInterface::class => ['getName'],
         AbstractDBElement::class => ['getID', '__toString'],
         TimeStampableInterface::class => ['getLastModified', 'getAddedDate'],
@@ -93,7 +93,7 @@ class SandboxedTwigProvider
             'getDepartment', 'getEmail']
 
     ];
-    protected const ALLOWED_PROPERTIES = [];
+    private const ALLOWED_PROPERTIES = [];
 
     private $appExtension;