diff --git a/src/Entity/Attachments/AttachmentContainingDBElement.php b/src/Entity/Attachments/AttachmentContainingDBElement.php
index e691e4f1..52b25264 100644
--- a/src/Entity/Attachments/AttachmentContainingDBElement.php
+++ b/src/Entity/Attachments/AttachmentContainingDBElement.php
@@ -25,6 +25,7 @@ namespace App\Entity\Attachments;
 
 use App\Entity\Base\MasterAttachmentTrait;
 use App\Entity\Base\AbstractNamedDBElement;
+use App\Entity\Contracts\HasMasterAttachmentInterface;
 use Doctrine\Common\Collections\ArrayCollection;
 use Doctrine\Common\Collections\Collection;
 use Doctrine\ORM\Mapping as ORM;
@@ -32,7 +33,7 @@ use Doctrine\ORM\Mapping as ORM;
 /**
  * @ORM\MappedSuperclass()
  */
-abstract class AttachmentContainingDBElement extends AbstractNamedDBElement
+abstract class AttachmentContainingDBElement extends AbstractNamedDBElement implements HasMasterAttachmentInterface
 {
     use MasterAttachmentTrait;
 
diff --git a/src/Entity/Base/AbstractNamedDBElement.php b/src/Entity/Base/AbstractNamedDBElement.php
index d1f8af1e..a34dbe7f 100644
--- a/src/Entity/Base/AbstractNamedDBElement.php
+++ b/src/Entity/Base/AbstractNamedDBElement.php
@@ -23,6 +23,7 @@ declare(strict_types=1);
 
 namespace App\Entity\Base;
 
+use App\Entity\Contracts\NamedElementInterface;
 use Doctrine\ORM\Mapping as ORM;
 use Symfony\Component\Serializer\Annotation\Groups;
 use Symfony\Component\Validator\Constraints as Assert;
@@ -33,7 +34,7 @@ use Symfony\Component\Validator\Constraints as Assert;
  * @ORM\MappedSuperclass(repositoryClass="App\Repository\UserRepository")
  * @ORM\HasLifecycleCallbacks()
  */
-abstract class AbstractNamedDBElement extends AbstractDBElement
+abstract class AbstractNamedDBElement extends AbstractDBElement implements NamedElementInterface
 {
     use TimestampTrait;
 
diff --git a/src/Entity/Contracts/HasAttachmentsInterface.php b/src/Entity/Contracts/HasAttachmentsInterface.php
new file mode 100644
index 00000000..d413aca8
--- /dev/null
+++ b/src/Entity/Contracts/HasAttachmentsInterface.php
@@ -0,0 +1,30 @@
+<?php
+/**
+ * This file is part of Part-DB (https://github.com/Part-DB/Part-DB-symfony).
+ *
+ * Copyright (C) 2019 - 2020 Jan Böhmer (https://github.com/jbtronics)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
+ */
+
+namespace App\Entity\Contracts;
+
+
+use Doctrine\Common\Collections\Collection;
+
+interface HasAttachmentsInterface
+{
+    public function getAttachments(): Collection;
+}
\ No newline at end of file
diff --git a/src/Entity/Contracts/HasMasterAttachmentInterface.php b/src/Entity/Contracts/HasMasterAttachmentInterface.php
new file mode 100644
index 00000000..fd3b12b3
--- /dev/null
+++ b/src/Entity/Contracts/HasMasterAttachmentInterface.php
@@ -0,0 +1,36 @@
+<?php
+/**
+ * This file is part of Part-DB (https://github.com/Part-DB/Part-DB-symfony).
+ *
+ * Copyright (C) 2019 - 2020 Jan Böhmer (https://github.com/jbtronics)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
+ */
+
+namespace App\Entity\Contracts;
+
+
+use App\Entity\Attachments\Attachment;
+
+interface HasMasterAttachmentInterface
+{
+    /**
+     * Get the master picture "Attachment"-object of this part (if there is one).
+     * The master picture should be used as a visual description/representation of this part.
+     *
+     * @return Attachment|null the master picture Attachment of this part (if there is one)
+     */
+    public function getMasterPictureAttachment(): ?Attachment;
+}
\ No newline at end of file
diff --git a/src/Entity/Contracts/NamedElementInterface.php b/src/Entity/Contracts/NamedElementInterface.php
new file mode 100644
index 00000000..46baed59
--- /dev/null
+++ b/src/Entity/Contracts/NamedElementInterface.php
@@ -0,0 +1,33 @@
+<?php
+/**
+ * This file is part of Part-DB (https://github.com/Part-DB/Part-DB-symfony).
+ *
+ * Copyright (C) 2019 - 2020 Jan Böhmer (https://github.com/jbtronics)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
+ */
+
+namespace App\Entity\Contracts;
+
+
+interface NamedElementInterface
+{
+    /**
+     * Get the name of this element.
+     *
+     * @return string the name of this element
+     */
+    public function getName(): string;
+}
\ No newline at end of file
diff --git a/src/Form/Type/MasterPictureAttachmentType.php b/src/Form/Type/MasterPictureAttachmentType.php
index fdeee5e9..0651f22d 100644
--- a/src/Form/Type/MasterPictureAttachmentType.php
+++ b/src/Form/Type/MasterPictureAttachmentType.php
@@ -26,6 +26,7 @@ namespace App\Form\Type;
 
 use App\Entity\Attachments\Attachment;
 use App\Entity\Attachments\AttachmentContainingDBElement;
+use App\Entity\Contracts\HasMasterAttachmentInterface;
 use Doctrine\ORM\EntityRepository;
 use ReflectionClass;
 use Symfony\Bridge\Doctrine\Form\Type\EntityType;
@@ -38,7 +39,7 @@ class MasterPictureAttachmentType extends AbstractType
     public function configureOptions(OptionsResolver $resolver): void
     {
         $resolver->setRequired('entity');
-        $resolver->setAllowedTypes('entity', AttachmentContainingDBElement::class);
+        $resolver->setAllowedTypes('entity', HasMasterAttachmentInterface::class);
 
         $resolver->setDefaults([
             'filter' => 'picture',
diff --git a/src/Services/ElementTypeNameGenerator.php b/src/Services/ElementTypeNameGenerator.php
index 72e4c205..a7e5eb5b 100644
--- a/src/Services/ElementTypeNameGenerator.php
+++ b/src/Services/ElementTypeNameGenerator.php
@@ -28,6 +28,7 @@ use App\Entity\Attachments\Attachment;
 use App\Entity\Attachments\AttachmentType;
 use App\Entity\Base\AbstractDBElement;
 use App\Entity\Base\AbstractNamedDBElement;
+use App\Entity\Contracts\NamedElementInterface;
 use App\Entity\Devices\Device;
 use App\Entity\Parts\Category;
 use App\Entity\Parts\Footprint;
@@ -113,14 +114,14 @@ class ElementTypeNameGenerator
      * For example this could be something like: "Part: BC547".
      * It uses getLocalizedLabel to determine the type.
      *
-     * @param AbstractNamedDBElement $entity   the entity for which the string should be generated
+     * @param NamedElementInterface $entity   the entity for which the string should be generated
      * @param bool           $use_html If set to true, a html string is returned, where the type is set italic
      *
      * @return string The localized string
      *
      * @throws EntityNotSupportedException when the passed entity is not supported
      */
-    public function getTypeNameCombination(AbstractNamedDBElement $entity, bool $use_html = false): string
+    public function getTypeNameCombination(NamedElementInterface $entity, bool $use_html = false): string
     {
         $type = $this->getLocalizedTypeLabel($entity);
         if ($use_html) {