diff --git a/src/Entity/Attachments/Attachment.php b/src/Entity/Attachments/Attachment.php
index 409320e1..96399fe2 100644
--- a/src/Entity/Attachments/Attachment.php
+++ b/src/Entity/Attachments/Attachment.php
@@ -59,7 +59,10 @@ abstract class Attachment extends NamedDBElement
     /**
      * When the path begins with one of this placeholders
      */
-    const INTERNAL_PLACEHOLDER = ['%BASE%', '%MEDIA%', '%FOOTPRINTS%', '%FOOTPRINTS3D%'];
+    const INTERNAL_PLACEHOLDER = ['%BASE%', '%MEDIA%'];
+
+    /** @var array Placeholders for attachments which using built in files. */
+    const BUILTIN_PLACEHOLDER = ['%FOOTPRINTS%', '%FOOTPRINTS3D%'];
 
     /**
      * @var bool
@@ -128,7 +131,17 @@ abstract class Attachment extends NamedDBElement
             return true;
         }
 
-        return !in_array($tmp[0], static::INTERNAL_PLACEHOLDER, false);
+        return !in_array($tmp[0], array_merge(static::INTERNAL_PLACEHOLDER, static::BUILTIN_PLACEHOLDER), false);
+    }
+
+    /**
+     * Checks if the attachment file is using a builtin file. (see BUILTIN_PLACEHOLDERS const for possible placeholders)
+     * If a file is built in, the path is shown to user in url field (no sensitive infos are provided)
+     * @return bool True if the attachment is uning an builtin file.
+     */
+    public function isBuiltIn() : bool
+    {
+        return static::checkIfBuiltin($this->path);
     }
 
     /********************************************************************************
@@ -167,13 +180,13 @@ abstract class Attachment extends NamedDBElement
     }
 
     /**
-     * The URL to the external file.
-     * Returns null, if the file is not external.
+     * The URL to the external file, or the path to the built in file.
+     * Returns null, if the file is not external (and not builtin).
      * @return string|null
      */
     public function getURL(): ?string
     {
-        if (!$this->isExternal()) {
+        if (!$this->isExternal() && !$this->isBuiltIn()) {
             return null;
         }
 
@@ -204,8 +217,6 @@ abstract class Attachment extends NamedDBElement
         return $this->path;
     }
 
-
-
     /**
      * Returns the filename of the attachment.
      * For a path like %BASE/path/foo.bar, foo.bar will be returned.
@@ -336,6 +347,22 @@ abstract class Attachment extends NamedDBElement
      * Static functions
      *****************************************************************************************************/
 
+    /**
+     * Checks if the given path is a path to a builtin ressource.
+     * @param string $path The path that should be checked
+     * @return bool True if the path is pointing to a builtin ressource.
+     */
+    public static function checkIfBuiltin(string $path) : bool
+    {
+        //After the %PLACEHOLDER% comes a slash, so we can check if we have a placholder via explode
+        $tmp = explode('/', $path);
+        //Builtins must have a %PLACEHOLDER% construction
+        if (empty($tmp)) {
+            return false;
+        }
+        return in_array($tmp[0], static::BUILTIN_PLACEHOLDER, false);
+    }
+
     /**
      * Check if a string is a URL and is valid.
      * @param $string string The string which should be checked.
diff --git a/src/EntityListeners/AttachmentDeleteListener.php b/src/EntityListeners/AttachmentDeleteListener.php
index 239ef65e..b2572063 100644
--- a/src/EntityListeners/AttachmentDeleteListener.php
+++ b/src/EntityListeners/AttachmentDeleteListener.php
@@ -66,6 +66,11 @@ class AttachmentDeleteListener
     public function preUpdateHandler(Attachment $attachment, PreUpdateEventArgs $event)
     {
         if ($event->hasChangedField('path')) {
+            //Dont delete file if the attachment uses a builtin ressource:
+            if (Attachment::checkIfBuiltin($event->getOldValue('path'))) {
+                return;
+            }
+
             $file = new \SplFileInfo($this->attachmentHelper->placeholderToRealPath($event->getOldValue('path')));
             $this->attachmentReverseSearch->deleteIfNotUsed($file);
         }
@@ -81,6 +86,11 @@ class AttachmentDeleteListener
      */
     public function postRemoveHandler(Attachment $attachment, LifecycleEventArgs $event)
     {
+        //Dont delete file if the attachment uses a builtin ressource:
+        if (Attachment::checkIfBuiltin($event->getOldValue('path'))) {
+            return;
+        }
+
         $file = $this->attachmentHelper->attachmentToFile($attachment);
         //Only delete if the attachment has a valid file.
         if ($file !== null) {
diff --git a/src/Form/AttachmentFormType.php b/src/Form/AttachmentFormType.php
index 61bf0054..d3edd9ec 100644
--- a/src/Form/AttachmentFormType.php
+++ b/src/Form/AttachmentFormType.php
@@ -37,6 +37,7 @@ use App\Entity\Attachments\AttachmentType;
 use App\Entity\Base\StructuralDBElement;
 use App\Form\Type\StructuralEntityType;
 use App\Services\AttachmentHelper;
+use App\Validator\Constraints\UrlOrBuiltin;
 use Symfony\Component\Form\AbstractType;
 use Symfony\Component\Form\Extension\Core\Type\CheckboxType;
 use Symfony\Component\Form\Extension\Core\Type\FileType;
@@ -75,11 +76,11 @@ class AttachmentFormType extends AbstractType
             'attr' => ['class' => 'form-control-sm'],
             'label_attr' => ['class' => 'checkbox-custom']]);
 
-        $builder->add('url', UrlType::class, [
+        $builder->add('url', TextType::class, [
             'label' =>  $this->trans->trans('attachment.edit.url'),
             'required' => false,
             'constraints' => [
-                new Url()
+                $options['allow_builtins'] ? new UrlOrBuiltin() : new Url()
             ]
         ]);
 
@@ -101,7 +102,8 @@ class AttachmentFormType extends AbstractType
     {
         $resolver->setDefaults([
             'data_class' => Attachment::class,
-            'max_file_size' => '16M'
+            'max_file_size' => '16M',
+            'allow_builtins' => true
         ]);
 
     }
diff --git a/src/Validator/Constraints/UrlOrBuiltin.php b/src/Validator/Constraints/UrlOrBuiltin.php
new file mode 100644
index 00000000..dcfcabc7
--- /dev/null
+++ b/src/Validator/Constraints/UrlOrBuiltin.php
@@ -0,0 +1,46 @@
+<?php
+/**
+ *
+ * part-db version 0.1
+ * Copyright (C) 2005 Christoph Lechner
+ * http://www.cl-projects.de/
+ *
+ * part-db version 0.2+
+ * Copyright (C) 2009 K. Jacobs and others (see authors.php)
+ * http://code.google.com/p/part-db/
+ *
+ * Part-DB Version 0.4+
+ * Copyright (C) 2016 - 2019 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\Validator\Constraints;
+
+
+use App\Entity\Attachments\Attachment;
+use Symfony\Component\Validator\Constraints\Url;
+
+/**
+ * Constraints the field that way that the content is either a url or a path to a builtin ressource (like %FOOTPRINTS%)
+ * @package App\Validator\Constraints
+ */
+class UrlOrBuiltin extends Url
+{
+    /** @var array A list of the placeholders that are treated as builtin */
+    public $allowed_placeholders = Attachment::BUILTIN_PLACEHOLDER;
+}
\ No newline at end of file
diff --git a/src/Validator/Constraints/UrlOrBuiltinValidator.php b/src/Validator/Constraints/UrlOrBuiltinValidator.php
new file mode 100644
index 00000000..04a8e83b
--- /dev/null
+++ b/src/Validator/Constraints/UrlOrBuiltinValidator.php
@@ -0,0 +1,76 @@
+<?php
+/**
+ *
+ * part-db version 0.1
+ * Copyright (C) 2005 Christoph Lechner
+ * http://www.cl-projects.de/
+ *
+ * part-db version 0.2+
+ * Copyright (C) 2009 K. Jacobs and others (see authors.php)
+ * http://code.google.com/p/part-db/
+ *
+ * Part-DB Version 0.4+
+ * Copyright (C) 2016 - 2019 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\Validator\Constraints;
+
+
+use Symfony\Component\Validator\Constraint;
+use Symfony\Component\Validator\Constraints\UrlValidator;
+use Symfony\Component\Validator\Exception\UnexpectedTypeException;
+use Symfony\Component\Validator\Exception\UnexpectedValueException;
+
+/**
+ * The validator for UrlOrBuiltin.
+ * It checks if the value is either a builtin ressource or a valid url.
+ * In both cases it is not checked, if the ressource is really existing.
+ * @package App\Validator\Constraints
+ */
+class UrlOrBuiltinValidator extends UrlValidator
+{
+    public function validate($value, Constraint $constraint)
+    {
+        if (!$constraint instanceof UrlOrBuiltin) {
+            throw new UnexpectedTypeException($constraint, UrlOrBuiltin::class);
+        }
+
+        if (null === $value || '' === $value) {
+            return;
+        }
+        if (!is_scalar($value) && !(\is_object($value) && method_exists($value, '__toString'))) {
+            throw new UnexpectedValueException($value, 'string');
+        }
+        $value = (string) $value;
+        if ('' === $value) {
+            return;
+        }
+
+        //After the %PLACEHOLDER% comes a slash, so we can check if we have a placholder via explode
+        $tmp = explode('/', $value);
+        //Builtins must have a %PLACEHOLDER% construction
+        if (!empty($tmp) && in_array($tmp[0], $constraint->allowed_placeholders, false)) {
+            return;
+        }
+
+        parent::validate($value, $constraint); // TODO: Change the autogenerated stub
+    }
+
+
+}
\ No newline at end of file
diff --git a/tests/Entity/AttachmentTest.php b/tests/Entity/AttachmentTest.php
index b02cf98a..998d9888 100644
--- a/tests/Entity/AttachmentTest.php
+++ b/tests/Entity/AttachmentTest.php
@@ -105,6 +105,27 @@ class AttachmentTest extends TestCase
         $this->assertTrue($attachment->isPicture());
     }
 
+    public function testIsBuiltIn()
+    {
+        $attachment = new PartAttachment();
+        $this->setProtectedProperty($attachment, 'path', '%MEDIA%/foo/bar.txt');
+        $this->assertFalse($attachment->isBuiltIn());
+
+        $this->setProtectedProperty($attachment, 'path', '%BASE%/foo/bar.txt');
+        $this->assertFalse($attachment->isBuiltIn());
+
+        $this->setProtectedProperty($attachment, 'path', '/');
+        $this->assertFalse($attachment->isBuiltIn());
+
+        $this->setProtectedProperty($attachment, 'path', 'https://google.de');
+        $this->assertFalse($attachment->isBuiltIn());
+
+        $this->setProtectedProperty($attachment, 'path', '%FOOTPRINTS%/foo/bar.txt');
+        $this->assertTrue($attachment->isBuiltIn());
+
+
+    }
+
     public function testGetHost()
     {
         $attachment = new PartAttachment();