diff --git a/openslides/agenda/access_permissions.py b/openslides/agenda/access_permissions.py
index 173dfbf58..47b85d1a4 100644
--- a/openslides/agenda/access_permissions.py
+++ b/openslides/agenda/access_permissions.py
@@ -1,9 +1,20 @@
-class AccessPermissions:
-    def get_serializer_class(self, user):
-        return None
+from ..utils.access_permissions import BaseAccessPermissions
 
+
+class ItemAccessPermissions(BaseAccessPermissions):
+    """
+    Access permissions container for Item and ItemViewSet.
+    """
     def can_retrieve(self, user):
         """
-        TODO
+        Returns True if the user has read access model instances.
         """
-        return user.has_perm('assignments.can_see')
+        return user.has_perm('agenda.can_see')
+
+    def get_serializer_class(self, user):
+        """
+        Returns serializer class.
+        """
+        from .serializers import ItemSerializer
+
+        return ItemSerializer
diff --git a/openslides/agenda/apps.py b/openslides/agenda/apps.py
index 6e0f2c913..a0c573577 100644
--- a/openslides/agenda/apps.py
+++ b/openslides/agenda/apps.py
@@ -33,4 +33,4 @@ class AgendaAppConfig(AppConfig):
             dispatch_uid='listen_to_related_object_post_delete')
 
         # Register viewsets.
-        router.register('agenda/item', ItemViewSet)
+        router.register(self.get_model('Item').get_collection_string(), ItemViewSet)
diff --git a/openslides/agenda/models.py b/openslides/agenda/models.py
index efd6c0d63..23483d59e 100644
--- a/openslides/agenda/models.py
+++ b/openslides/agenda/models.py
@@ -15,6 +15,8 @@ from openslides.utils.exceptions import OpenSlidesError
 from openslides.utils.models import RESTModelMixin
 from openslides.utils.utils import to_roman
 
+from .access_permissions import ItemAccessPermissions
+
 
 class ItemManager(models.Manager):
     """
@@ -184,6 +186,7 @@ class Item(RESTModelMixin, models.Model):
     """
     An Agenda Item
     """
+    access_permissions = ItemAccessPermissions()
     objects = ItemManager()
 
     AGENDA_ITEM = 1
diff --git a/openslides/agenda/views.py b/openslides/agenda/views.py
index d680d5f92..0fd57a092 100644
--- a/openslides/agenda/views.py
+++ b/openslides/agenda/views.py
@@ -7,7 +7,6 @@ from django.utils.translation import ugettext_lazy
 from reportlab.platypus import Paragraph
 
 from openslides.core.config import config
-from openslides.agenda.access_permissions import AccessPermissions
 from openslides.utils.exceptions import OpenSlidesError
 from openslides.utils.pdf import stylesheet
 from openslides.utils.rest_api import (
@@ -22,8 +21,8 @@ from openslides.utils.rest_api import (
 )
 from openslides.utils.views import PDFView
 
+from .access_permissions import ItemAccessPermissions
 from .models import Item, Speaker
-from .serializers import ItemSerializer
 
 
 # Viewsets for the REST API
@@ -35,16 +34,15 @@ class ItemViewSet(ListModelMixin, RetrieveModelMixin, UpdateModelMixin, GenericV
     There are the following views: metadata, list, retrieve, create,
     partial_update, update, destroy, manage_speaker, speak and tree.
     """
+    access_permissions = ItemAccessPermissions()
     queryset = Item.objects.all()
-    serializer_class = ItemSerializer
-    access_permissions = AccessPermissions()
 
     def check_view_permissions(self):
         """
         Returns True if the user has required permissions.
         """
         if self.action == 'retrieve':
-            result = self.access_permissions.can_retrieve(self.request.user)
+            result = self.get_access_permissions().can_retrieve(self.request.user)
         elif self.action in ('metadata', 'list', 'manage_speaker', 'tree'):
             result = self.request.user.has_perm('agenda.can_see')
             # For manage_speaker and tree requests the rest of the check is
@@ -65,6 +63,7 @@ class ItemViewSet(ListModelMixin, RetrieveModelMixin, UpdateModelMixin, GenericV
         Checks if the requesting user has permission to see also an
         organizational item if it is one.
         """
+        #TODO
         if obj.is_hidden() and not request.user.has_perm('agenda.can_see_hidden_items'):
             self.permission_denied(request)
 
diff --git a/openslides/assignments/access_permissions.py b/openslides/assignments/access_permissions.py
index f31b0c528..9391068b4 100644
--- a/openslides/assignments/access_permissions.py
+++ b/openslides/assignments/access_permissions.py
@@ -1,18 +1,24 @@
+from ..utils.access_permissions import BaseAccessPermissions
+
+
+class AssignmentAccessPermissions(BaseAccessPermissions):
+    """
+    Access permissions container for Assignment and AssignmentViewSet.
+    """
+    def can_retrieve(self, user):
+        """
+        Returns True if the user has read access model instances.
+        """
+        return user.has_perm('assignments.can_see')
 
-class AccessPermissions:
     def get_serializer_class(self, user):
         """
         Returns different serializer classes according to users permissions.
         """
-        from openslides.assignments.serializers import AssignmentFullSerializer, AssignmentShortSerializer
+        from .serializers import AssignmentFullSerializer, AssignmentShortSerializer
+
         if user.has_perm('assignments.can_manage'):
             serializer_class = AssignmentFullSerializer
         else:
             serializer_class = AssignmentShortSerializer
         return serializer_class
-
-    def can_retrieve(self, user):
-        """
-        TODO
-        """
-        return user.has_perm('agenda.can_see')
diff --git a/openslides/assignments/apps.py b/openslides/assignments/apps.py
index 7fa797c72..adc090c04 100644
--- a/openslides/assignments/apps.py
+++ b/openslides/assignments/apps.py
@@ -22,5 +22,5 @@ class AssignmentsAppConfig(AppConfig):
         config_signal.connect(setup_assignment_config, dispatch_uid='setup_assignment_config')
 
         # Register viewsets.
-        router.register(self.get_model('Assignment').get_collection_name(), AssignmentViewSet)
+        router.register(self.get_model('Assignment').get_collection_string(), AssignmentViewSet)
         router.register('assignments/poll', AssignmentPollViewSet)
diff --git a/openslides/assignments/models.py b/openslides/assignments/models.py
index f32ef95f3..f777369c5 100644
--- a/openslides/assignments/models.py
+++ b/openslides/assignments/models.py
@@ -7,7 +7,6 @@ from django.utils.translation import ugettext as _
 from django.utils.translation import ugettext_lazy, ugettext_noop
 
 from openslides.agenda.models import Item, Speaker
-from openslides.assignments.access_permissions import AccessPermissions
 from openslides.core.config import config
 from openslides.core.models import Tag
 from openslides.poll.models import (
@@ -21,6 +20,8 @@ from openslides.utils.exceptions import OpenSlidesError
 from openslides.utils.models import RESTModelMixin
 from openslides.utils.search import user_name_helper
 
+from .access_permissions import AssignmentAccessPermissions
+
 
 class AssignmentRelatedUser(RESTModelMixin, models.Model):
     """
@@ -50,7 +51,10 @@ class AssignmentRelatedUser(RESTModelMixin, models.Model):
 
 
 class Assignment(RESTModelMixin, models.Model):
-    access_permissions = AccessPermissions()
+    """
+    Model for assignments.
+    """
+    access_permissions = AssignmentAccessPermissions()
 
     PHASE_SEARCH = 0
     PHASE_VOTING = 1
diff --git a/openslides/assignments/views.py b/openslides/assignments/views.py
index 7071b1db6..9a88e5465 100644
--- a/openslides/assignments/views.py
+++ b/openslides/assignments/views.py
@@ -17,7 +17,6 @@ from reportlab.platypus import (
     TableStyle,
 )
 
-from openslides.assignments.access_permissions import AccessPermissions
 from openslides.core.config import config
 from openslides.utils.pdf import stylesheet
 from openslides.utils.rest_api import (
@@ -31,12 +30,9 @@ from openslides.utils.rest_api import (
 )
 from openslides.utils.views import PDFView
 
+from .access_permissions import AssignmentAccessPermissions
 from .models import Assignment, AssignmentPoll
-from .serializers import (
-    AssignmentAllPollSerializer,
-    AssignmentFullSerializer,
-    AssignmentShortSerializer,
-)
+from .serializers import AssignmentAllPollSerializer
 
 
 # Viewsets for the REST API
@@ -49,15 +45,15 @@ class AssignmentViewSet(ModelViewSet):
     partial_update, update, destroy, candidature_self, candidature_other,
     mark_elected and create_poll.
     """
+    access_permissions = AssignmentAccessPermissions()
     queryset = Assignment.objects.all()
-    access_permissions = AccessPermissions()
 
     def check_view_permissions(self):
         """
         Returns True if the user has required permissions.
         """
         if self.action == 'retrieve':
-            result = self.access_permissions.can_retrieve(self.request.user)
+            result = self.get_access_permissions().can_retrieve(self.request.user)
         elif self.action in ('metadata', 'list'):
             result = self.request.user.has_perm('assignments.can_see')
         elif self.action in ('create', 'partial_update', 'update', 'destroy',
diff --git a/openslides/core/access_permissions.py b/openslides/core/access_permissions.py
index 38985369b..458c3cc43 100644
--- a/openslides/core/access_permissions.py
+++ b/openslides/core/access_permissions.py
@@ -1,9 +1,109 @@
-class AccessPermissions:
-    def get_serializer_class(self, user):
-        return None
+from ..utils.access_permissions import BaseAccessPermissions
 
+
+class ProjectorAccessPermissions(BaseAccessPermissions):
+    """
+    Access permissions container for Projector and ProjectorViewSet.
+    """
     def can_retrieve(self, user):
         """
-        TODO
+        Returns True if the user has read access model instances.
         """
         return user.has_perm('core.can_see_projector')
+
+    def get_serializer_class(self, user):
+        """
+        Returns serializer class.
+        """
+        from .serializers import ProjectorSerializer
+
+        return ProjectorSerializer
+
+
+class CustomSlideAccessPermissions(BaseAccessPermissions):
+    """
+    Access permissions container for CustomSlide and CustomSlideViewSet.
+    """
+    def can_retrieve(self, user):
+        """
+        Returns True if the user has read access model instances.
+        """
+        return user.has_perm('core.can_manage_projector')
+
+    def get_serializer_class(self, user):
+        """
+        Returns serializer class.
+        """
+        from .serializers import CustomSlideSerializer
+
+        return CustomSlideSerializer
+
+
+class TagAccessPermissions(BaseAccessPermissions):
+    """
+    Access permissions container for Tag and TagViewSet.
+    """
+    def can_retrieve(self, user):
+        """
+        Returns True if the user has read access model instances.
+        """
+        from .config import config
+
+        # Every authenticated user can retrieve tags. Anonymous users can do
+        # so if they are enabled.
+        return user.is_authenticated() or config['general_system_enable_anonymous']
+
+    def get_serializer_class(self, user):
+        """
+        Returns serializer class.
+        """
+        from .serializers import TagSerializer
+
+        return TagSerializer
+
+
+class ChatMessageAccessPermissions(BaseAccessPermissions):
+    """
+    Access permissions container for ChatMessage and ChatMessageViewSet.
+    """
+    def can_retrieve(self, user):
+        """
+        Returns True if the user has read access model instances.
+        """
+        # Anonymous users can see the chat if the anonymous group has the
+        # permission core.can_use_chat. But they can not use it. See views.py.
+        return user.has_perm('core.can_use_chat')
+
+    def get_serializer_class(self, user):
+        """
+        Returns serializer class.
+        """
+        from .serializers import ChatMessageSerializer
+
+        return ChatMessageSerializer
+
+
+class ConfigAccessPermissions(BaseAccessPermissions):
+    """
+    Access permissions container for the config (ConfigStore and
+    ConfigViewSet).
+    """
+    def can_retrieve(self, user):
+        """
+        Returns True if the user has read access model instances.
+        """
+        from .config import config
+
+        # Every authenticated user can see the metadata and list or retrieve
+        # the config. Anonymous users can do so if they are enabled.
+        return user.is_authenticated() or config['general_system_enable_anonymous']
+
+    def get_serialized_data(self, instance, user):
+        """
+        Returns the serlialized config data or None if the user is not
+        allowed to see it.
+        """
+        from .config import config
+
+        if self.can_retrieve(user) is not None:
+            return {'key': instance.key, 'value': config[instance.key]}
diff --git a/openslides/core/apps.py b/openslides/core/apps.py
index ef99c6d88..456d08552 100644
--- a/openslides/core/apps.py
+++ b/openslides/core/apps.py
@@ -12,11 +12,11 @@ class CoreAppConfig(AppConfig):
         # Load projector elements.
         # Do this by just importing all from these files.
         from . import projector  # noqa
+
         # Import all required stuff.
         from django.db.models import signals
         from openslides.core.signals import config_signal, post_permission_creation
-        from openslides.utils.autoupdate import inform_changed_data_receiver
-        from openslides.utils.autoupdate import inform_deleted_data_receiver
+        from openslides.utils.autoupdate import inform_changed_data_receiver, inform_deleted_data_receiver
         from openslides.utils.rest_api import router
         from openslides.utils.search import index_add_instance, index_del_instance
         from .signals import delete_django_app_permissions, setup_general_config
@@ -37,11 +37,11 @@ class CoreAppConfig(AppConfig):
             dispatch_uid='delete_django_app_permissions')
 
         # Register viewsets.
-        router.register('core/projector', ProjectorViewSet)
-        router.register('core/chatmessage', ChatMessageViewSet)
-        router.register('core/customslide', CustomSlideViewSet)
-        router.register('core/tag', TagViewSet)
-        router.register('core/config', ConfigViewSet, 'config')
+        router.register(self.get_model('Projector').get_collection_string(), ProjectorViewSet)
+        router.register(self.get_model('ChatMessage').get_collection_string(), ChatMessageViewSet)
+        router.register(self.get_model('CustomSlide').get_collection_string(), CustomSlideViewSet)
+        router.register(self.get_model('Tag').get_collection_string(), TagViewSet)
+        router.register(self.get_model('ConfigStore').get_collection_string(), ConfigViewSet, 'config')
 
         # Update data when any model of any installed app is saved or deleted.
         # TODO: Test if the m2m_changed signal is also needed.
diff --git a/openslides/core/models.py b/openslides/core/models.py
index 843d9dd0e..fe2f50e0f 100644
--- a/openslides/core/models.py
+++ b/openslides/core/models.py
@@ -1,6 +1,5 @@
 from django.conf import settings
 from django.contrib.contenttypes.models import ContentType
-from django.core.urlresolvers import reverse
 from django.db import models
 from jsonfield import JSONField
 
@@ -8,6 +7,13 @@ from openslides.mediafiles.models import Mediafile
 from openslides.utils.models import RESTModelMixin
 from openslides.utils.projector import ProjectorElement
 
+from .access_permissions import (
+    ChatMessageAccessPermissions,
+    ConfigAccessPermissions,
+    CustomSlideAccessPermissions,
+    ProjectorAccessPermissions,
+    TagAccessPermissions,
+)
 from .exceptions import ProjectorException
 
 
@@ -51,6 +57,8 @@ class Projector(RESTModelMixin, models.Model):
     The projector can be controlled using the REST API with POST requests
     on e. g. the URL /rest/core/projector/1/activate_elements/.
     """
+    access_permissions = ProjectorAccessPermissions()
+
     config = JSONField()
 
     scale = models.IntegerField(default=0)
@@ -121,6 +129,8 @@ class CustomSlide(RESTModelMixin, models.Model):
     """
     Model for slides with custom content.
     """
+    access_permissions = CustomSlideAccessPermissions()
+
     title = models.CharField(
         max_length=256)
     text = models.TextField(
@@ -175,6 +185,8 @@ class Tag(RESTModelMixin, models.Model):
     Model for tags. This tags can be used for other models like agenda items,
     motions or assignments.
     """
+    access_permissions = TagAccessPermissions()
+
     name = models.CharField(
         max_length=255,
         unique=True)
@@ -189,10 +201,11 @@ class Tag(RESTModelMixin, models.Model):
         return self.name
 
 
-class ConfigStore(models.Model):
+class ConfigStore(RESTModelMixin, models.Model):
     """
     A model class to store all config variables in the database.
     """
+    access_permissions = ConfigAccessPermissions()
 
     key = models.CharField(max_length=255, unique=True, db_index=True)
     """A string, the key of the config variable."""
@@ -205,11 +218,15 @@ class ConfigStore(models.Model):
         permissions = (
             ('can_manage_config', 'Can manage configuration'),)
 
-    def get_root_rest_url(self):
+    @classmethod
+    def get_collection_string(cls):
+        return 'core/config'
+
+    def get_rest_pk(self):
         """
-        Returns the detail url of config value.
+        Returns the primary key used in the REST API.
         """
-        return reverse('config-detail', args=[str(self.key)])
+        return self.key
 
 
 class ChatMessage(RESTModelMixin, models.Model):
@@ -218,6 +235,8 @@ class ChatMessage(RESTModelMixin, models.Model):
 
     At the moment we only have one global chat room for managers.
     """
+    access_permissions = ChatMessageAccessPermissions()
+
     message = models.TextField()
 
     timestamp = models.DateTimeField(auto_now_add=True)
diff --git a/openslides/core/views.py b/openslides/core/views.py
index 52f3e0575..5cf070389 100644
--- a/openslides/core/views.py
+++ b/openslides/core/views.py
@@ -13,7 +13,6 @@ from django.http import Http404, HttpResponse
 from django.utils.timezone import now
 
 from openslides import __version__ as version
-from openslides.core.access_permissions import AccessPermissions
 from openslides.utils import views as utils_views
 from openslides.utils.plugins import (
     get_plugin_description,
@@ -31,15 +30,16 @@ from openslides.utils.rest_api import (
 )
 from openslides.utils.search import search
 
+from .access_permissions import (
+    ChatMessageAccessPermissions,
+    ConfigAccessPermissions,
+    CustomSlideAccessPermissions,
+    ProjectorAccessPermissions,
+    TagAccessPermissions,
+)
 from .config import config
 from .exceptions import ConfigError, ConfigNotFound
 from .models import ChatMessage, CustomSlide, Projector, Tag
-from .serializers import (
-    ChatMessageSerializer,
-    CustomSlideSerializer,
-    ProjectorSerializer,
-    TagSerializer,
-)
 
 
 # Special Django views
@@ -153,16 +153,15 @@ class ProjectorViewSet(ReadOnlyModelViewSet):
     activate_elements, prune_elements, update_elements,
     deactivate_elements, clear_elements and control_view.
     """
+    access_permissions = ProjectorAccessPermissions()
     queryset = Projector.objects.all()
-    serializer_class = ProjectorSerializer
-    access_permissions = AccessPermissions()
 
     def check_view_permissions(self):
         """
         Returns True if the user has required permissions.
         """
         if self.action == 'retrieve':
-            result = self.access_permissions.can_retrieve(self.request.user)
+            result = self.get_access_permissions().can_retrieve(self.request.user)
         elif self.action in ('metadata', 'list'):
             result = self.request.user.has_perm('core.can_see_projector')
         elif self.action in ('activate_elements', 'prune_elements', 'update_elements',
@@ -370,14 +369,18 @@ class CustomSlideViewSet(ModelViewSet):
     There are the following views: metadata, list, retrieve, create,
     partial_update, update and destroy.
     """
+    access_permissions = CustomSlideAccessPermissions()
     queryset = CustomSlide.objects.all()
-    serializer_class = CustomSlideSerializer
 
     def check_view_permissions(self):
         """
         Returns True if the user has required permissions.
         """
-        return self.request.user.has_perm('core.can_manage_projector')
+        if self.action == 'retrieve':
+            result = self.get_access_permissions().can_retrieve(self.request.user)
+        else:
+            result = self.request.user.has_perm('core.can_manage_projector')
+        return result
 
 
 class TagViewSet(ModelViewSet):
@@ -387,16 +390,18 @@ class TagViewSet(ModelViewSet):
     There are the following views: metadata, list, retrieve, create,
     partial_update, update and destroy.
     """
+    access_permissions = TagAccessPermissions()
     queryset = Tag.objects.all()
-    serializer_class = TagSerializer
 
     def check_view_permissions(self):
         """
         Returns True if the user has required permissions.
         """
-        if self.action in ('metadata', 'list', 'retrieve'):
-            # Every authenticated user can see the metadata and list or
-            # retrieve tags. Anonymous users can do so if they are enabled.
+        if self.action == 'retrieve':
+            result = self.get_access_permissions().can_retrieve(self.request.user)
+        elif self.action in ('metadata', 'list'):
+            # Every authenticated user can see the metadata and list tags.
+            # Anonymous users can do so if they are enabled.
             result = self.request.user.is_authenticated() or config['general_system_enable_anonymous']
         elif self.action in ('create', 'update', 'destroy'):
             result = self.request.user.has_perm('core.can_manage_tags')
@@ -444,13 +449,16 @@ class ConfigViewSet(ViewSet):
 
     There are the following views: metadata, list, retrieve and update.
     """
+    access_permissions = ConfigAccessPermissions()
     metadata_class = ConfigMetadata
 
     def check_view_permissions(self):
         """
         Returns True if the user has required permissions.
         """
-        if self.action in ('metadata', 'list', 'retrieve'):
+        if self.action == 'retrieve':
+            result = self.get_access_permissions().can_retrieve(self.request.user)
+        elif self.action in ('metadata', 'list'):
             # Every authenticated user can see the metadata and list or
             # retrieve the config. Anonymous users can do so if they are
             # enabled.
@@ -476,6 +484,8 @@ class ConfigViewSet(ViewSet):
             value = config[key]
         except ConfigNotFound:
             raise Http404
+        # Attention: The format of this response has to be the same as in
+        # the get_serialized_data method of ConfigAccessPermissions.
         return Response({'key': key, 'value': value})
 
     def update(self, request, *args, **kwargs):
@@ -508,18 +518,23 @@ class ChatMessageViewSet(ModelViewSet):
     There are the following views: metadata, list, retrieve and create.
     The views partial_update, update and destroy are disabled.
     """
+    access_permissions = ChatMessageAccessPermissions()
     queryset = ChatMessage.objects.all()
-    serializer_class = ChatMessageSerializer
 
     def check_view_permissions(self):
         """
         Returns True if the user has required permissions.
         """
-        # We do not want anonymous users to use the chat even the anonymous
-        # group has the permission core.can_use_chat.
-        return (self.action in ('metadata', 'list', 'retrieve', 'create') and
+        if self.action == 'retrieve':
+            result = self.get_access_permissions().can_retrieve(self.request.user)
+        else:
+            # We do not want anonymous users to use the chat even the anonymous
+            # group has the permission core.can_use_chat.
+            result = (
+                self.action in ('metadata', 'list', 'create') and
                 self.request.user.is_authenticated() and
                 self.request.user.has_perm('core.can_use_chat'))
+        return result
 
     def perform_create(self, serializer):
         """
diff --git a/openslides/mediafiles/access_permissions.py b/openslides/mediafiles/access_permissions.py
new file mode 100644
index 000000000..832b9bffa
--- /dev/null
+++ b/openslides/mediafiles/access_permissions.py
@@ -0,0 +1,20 @@
+from ..utils.access_permissions import BaseAccessPermissions
+
+
+class MediafileAccessPermissions(BaseAccessPermissions):
+    """
+    Access permissions container for Mediafile and MediafileViewSet.
+    """
+    def can_retrieve(self, user):
+        """
+        Returns True if the user has read access model instances.
+        """
+        return user.has_perm('mediafiles.can_see')
+
+    def get_serializer_class(self, user):
+        """
+        Returns serializer class.
+        """
+        from .serializers import MediafileSerializer
+
+        return MediafileSerializer
diff --git a/openslides/mediafiles/apps.py b/openslides/mediafiles/apps.py
index 78c4d673a..8f2b69dcf 100644
--- a/openslides/mediafiles/apps.py
+++ b/openslides/mediafiles/apps.py
@@ -18,4 +18,4 @@ class MediafilesAppConfig(AppConfig):
         from .views import MediafileViewSet
 
         # Register viewsets.
-        router.register('mediafiles/mediafile', MediafileViewSet)
+        router.register(self.get_model('Mediafile').get_collection_string(), MediafileViewSet)
diff --git a/openslides/mediafiles/models.py b/openslides/mediafiles/models.py
index d387bdb19..037c717b3 100644
--- a/openslides/mediafiles/models.py
+++ b/openslides/mediafiles/models.py
@@ -5,12 +5,15 @@ from django.utils.translation import ugettext as _
 from openslides.utils.search import user_name_helper
 
 from ..utils.models import RESTModelMixin
+from .access_permissions import MediafileAccessPermissions
 
 
 class Mediafile(RESTModelMixin, models.Model):
     """
     Class for uploaded files which can be delivered under a certain url.
     """
+    access_permissions = MediafileAccessPermissions()
+
     mediafile = models.FileField(upload_to='file')
     """
     See https://docs.djangoproject.com/en/dev/ref/models/fields/#filefield
diff --git a/openslides/mediafiles/views.py b/openslides/mediafiles/views.py
index e39ed9339..f6a598cef 100644
--- a/openslides/mediafiles/views.py
+++ b/openslides/mediafiles/views.py
@@ -1,6 +1,6 @@
 from ..utils.rest_api import ModelViewSet, ValidationError
+from .access_permissions import MediafileAccessPermissions
 from .models import Mediafile
-from .serializers import MediafileSerializer
 
 
 # Viewsets for the REST API
@@ -12,14 +12,16 @@ class MediafileViewSet(ModelViewSet):
     There are the following views: metadata, list, retrieve, create,
     partial_update, update and destroy.
     """
+    access_permissions = MediafileAccessPermissions()
     queryset = Mediafile.objects.all()
-    serializer_class = MediafileSerializer
 
     def check_view_permissions(self):
         """
         Returns True if the user has required permissions.
         """
-        if self.action in ('metadata', 'list', 'retrieve'):
+        if self.action == 'retrieve':
+            result = self.get_access_permissions().can_retrieve(self.request.user)
+        elif self.action in ('metadata', 'list'):
             result = self.request.user.has_perm('mediafiles.can_see')
         elif self.action == 'create':
             result = (self.request.user.has_perm('mediafiles.can_see') and
diff --git a/openslides/motions/access_permissions.py b/openslides/motions/access_permissions.py
new file mode 100644
index 000000000..10c1cf01c
--- /dev/null
+++ b/openslides/motions/access_permissions.py
@@ -0,0 +1,58 @@
+from ..utils.access_permissions import BaseAccessPermissions
+
+
+class MotionAccessPermissions(BaseAccessPermissions):
+    """
+    Access permissions container for Motion and MotionViewSet.
+    """
+    def can_retrieve(self, user):
+        """
+        Returns True if the user has read access model instances.
+        """
+        return user.has_perm('motions.can_see')
+
+    def get_serializer_class(self, user):
+        """
+        Returns serializer class.
+        """
+        from .serializers import MotionSerializer
+
+        return MotionSerializer
+
+
+class CategoryAccessPermissions(BaseAccessPermissions):
+    """
+    Access permissions container for Category and CategoryViewSet.
+    """
+    def can_retrieve(self, user):
+        """
+        Returns True if the user has read access model instances.
+        """
+        return user.has_perm('motions.can_see')
+
+    def get_serializer_class(self, user):
+        """
+        Returns serializer class.
+        """
+        from .serializers import CategorySerializer
+
+        return CategorySerializer
+
+
+class WorkflowAccessPermissions(BaseAccessPermissions):
+    """
+    Access permissions container for Workflow and WorkflowViewSet.
+    """
+    def can_retrieve(self, user):
+        """
+        Returns True if the user has read access model instances.
+        """
+        return user.has_perm('motions.can_see')
+
+    def get_serializer_class(self, user):
+        """
+        Returns serializer class.
+        """
+        from .serializers import WorkflowSerializer
+
+        return WorkflowSerializer
diff --git a/openslides/motions/apps.py b/openslides/motions/apps.py
index 20f5626e6..582090fb5 100644
--- a/openslides/motions/apps.py
+++ b/openslides/motions/apps.py
@@ -25,7 +25,7 @@ class MotionsAppConfig(AppConfig):
         post_migrate.connect(create_builtin_workflows, dispatch_uid='motion_create_builtin_workflows')
 
         # Register viewsets.
-        router.register('motions/category', CategoryViewSet)
-        router.register('motions/motion', MotionViewSet)
+        router.register(self.get_model('Category').get_collection_string(), CategoryViewSet)
+        router.register(self.get_model('Motion').get_collection_string(), MotionViewSet)
+        router.register(self.get_model('Workflow').get_collection_string(), WorkflowViewSet)
         router.register('motions/motionpoll', MotionPollViewSet)
-        router.register('motions/workflow', WorkflowViewSet)
diff --git a/openslides/motions/models.py b/openslides/motions/models.py
index 2c24416c9..4f51ab033 100644
--- a/openslides/motions/models.py
+++ b/openslides/motions/models.py
@@ -20,6 +20,11 @@ from openslides.poll.models import (
 from openslides.utils.models import RESTModelMixin
 from openslides.utils.search import user_name_helper
 
+from .access_permissions import (
+    CategoryAccessPermissions,
+    MotionAccessPermissions,
+    WorkflowAccessPermissions,
+)
 from .exceptions import WorkflowError
 
 
@@ -29,6 +34,7 @@ class Motion(RESTModelMixin, models.Model):
 
     This class is the main entry point to all other classes related to a motion.
     """
+    access_permissions = MotionAccessPermissions()
 
     active_version = models.ForeignKey(
         'MotionVersion',
@@ -624,6 +630,11 @@ class MotionVersion(RESTModelMixin, models.Model):
 
 
 class Category(RESTModelMixin, models.Model):
+    """
+    Model for categories of motions.
+    """
+    access_permissions = CategoryAccessPermissions()
+
     name = models.CharField(max_length=255)
     """Name of the category."""
 
@@ -879,7 +890,10 @@ class State(RESTModelMixin, models.Model):
 
 
 class Workflow(RESTModelMixin, models.Model):
-    """Defines a workflow for a motion."""
+    """
+    Defines a workflow for a motion.
+    """
+    access_permissions = WorkflowAccessPermissions()
 
     name = models.CharField(max_length=255)
     """A string representing the workflow."""
diff --git a/openslides/motions/views.py b/openslides/motions/views.py
index 8af5de929..cb10330bd 100644
--- a/openslides/motions/views.py
+++ b/openslides/motions/views.py
@@ -18,15 +18,15 @@ from openslides.utils.rest_api import (
 )
 from openslides.utils.views import PDFView, SingleObjectMixin
 
+from .access_permissions import (
+    CategoryAccessPermissions,
+    MotionAccessPermissions,
+    WorkflowAccessPermissions,
+)
 from .exceptions import WorkflowError
 from .models import Category, Motion, MotionPoll, MotionVersion, Workflow
 from .pdf import motion_poll_to_pdf, motion_to_pdf, motions_to_pdf
-from .serializers import (
-    CategorySerializer,
-    MotionPollSerializer,
-    MotionSerializer,
-    WorkflowSerializer,
-)
+from .serializers import MotionPollSerializer
 
 
 # Viewsets for the REST API
@@ -39,14 +39,16 @@ class MotionViewSet(ModelViewSet):
     partial_update, update, destroy, manage_version, support, set_state and
     create_poll.
     """
+    access_permissions = MotionAccessPermissions()
     queryset = Motion.objects.all()
-    serializer_class = MotionSerializer
 
     def check_view_permissions(self):
         """
         Returns True if the user has required permissions.
         """
-        if self.action in ('metadata', 'list', 'retrieve', 'partial_update', 'update'):
+        if self.action == 'retrieve':
+            result = self.get_access_permissions().can_retrieve(self.request.user)
+        elif self.action in ('metadata', 'list', 'partial_update', 'update'):
             result = self.request.user.has_perm('motions.can_see')
             # For partial_update and update requests the rest of the check is
             # done in the update method. See below.
@@ -281,14 +283,16 @@ class CategoryViewSet(ModelViewSet):
     There are the following views: metadata, list, retrieve, create,
     partial_update, update and destroy.
     """
+    access_permissions = CategoryAccessPermissions()
     queryset = Category.objects.all()
-    serializer_class = CategorySerializer
 
     def check_view_permissions(self):
         """
         Returns True if the user has required permissions.
         """
-        if self.action in ('metadata', 'list', 'retrieve'):
+        if self.action == 'retrieve':
+            result = self.get_access_permissions().can_retrieve(self.request.user)
+        elif self.action in ('metadata', 'list'):
             result = self.request.user.has_perm('motions.can_see')
         elif self.action in ('create', 'partial_update', 'update', 'destroy'):
             result = (self.request.user.has_perm('motions.can_see') and
@@ -305,14 +309,16 @@ class WorkflowViewSet(ModelViewSet):
     There are the following views: metadata, list, retrieve, create,
     partial_update, update and destroy.
     """
+    access_permissions = WorkflowAccessPermissions()
     queryset = Workflow.objects.all()
-    serializer_class = WorkflowSerializer
 
     def check_view_permissions(self):
         """
         Returns True if the user has required permissions.
         """
-        if self.action in ('metadata', 'list', 'retrieve'):
+        if self.action == 'retrieve':
+            result = self.get_access_permissions().can_retrieve(self.request.user)
+        elif self.action in ('metadata', 'list'):
             result = self.request.user.has_perm('motions.can_see')
         elif self.action in ('create', 'partial_update', 'update', 'destroy'):
             result = (self.request.user.has_perm('motions.can_see') and
diff --git a/openslides/users/access_permissions.py b/openslides/users/access_permissions.py
new file mode 100644
index 000000000..675fdd603
--- /dev/null
+++ b/openslides/users/access_permissions.py
@@ -0,0 +1,26 @@
+from ..utils.access_permissions import BaseAccessPermissions
+
+
+class UserAccessPermissions(BaseAccessPermissions):
+    """
+    Access permissions container for User and UserViewSet.
+    """
+    def can_retrieve(self, user):
+        """
+        Returns True if the user has read access model instances.
+        """
+        return user.has_perm('users.can_see_name')
+
+    def get_serializer_class(self, user):
+        """
+        Returns different serializer classes with respect user's permissions.
+        """
+        from .serializers import UserFullSerializer, UserShortSerializer
+
+        if user.has_perm('users.can_see_extra_data'):
+            # Return the UserFullSerializer for requests of users with more
+            # permissions.
+            serializer_class = UserFullSerializer
+        else:
+            serializer_class = UserShortSerializer
+        return serializer_class
diff --git a/openslides/users/apps.py b/openslides/users/apps.py
index 3b36eda7e..623adc8f0 100644
--- a/openslides/users/apps.py
+++ b/openslides/users/apps.py
@@ -28,5 +28,5 @@ class UsersAppConfig(AppConfig):
             dispatch_uid='create_builtin_groups_and_admin')
 
         # Register viewsets.
-        router.register('users/user', UserViewSet)
+        router.register(self.get_model('User').get_collection_string(), UserViewSet)
         router.register('users/group', GroupViewSet)
diff --git a/openslides/users/models.py b/openslides/users/models.py
index 3c56ad55d..3fdb3295c 100644
--- a/openslides/users/models.py
+++ b/openslides/users/models.py
@@ -13,6 +13,7 @@ from openslides.utils.search import user_name_helper
 
 from ..core.config import config
 from ..utils.models import RESTModelMixin
+from .access_permissions import UserAccessPermissions
 from .exceptions import UsersError
 
 
@@ -94,6 +95,8 @@ class User(RESTModelMixin, PermissionsMixin, AbstractBaseUser):
     in other OpenSlides apps like motion submitter or (assignment) election
     candidates.
     """
+    access_permissions = UserAccessPermissions()
+
     USERNAME_FIELD = 'username'
 
     username = models.CharField(
diff --git a/openslides/users/views.py b/openslides/users/views.py
index 111f63390..1591691ff 100644
--- a/openslides/users/views.py
+++ b/openslides/users/views.py
@@ -14,13 +14,10 @@ from ..utils.rest_api import (
     status,
 )
 from ..utils.views import APIView, PDFView
+from .access_permissions import UserAccessPermissions
 from .models import Group, User
 from .pdf import users_passwords_to_pdf, users_to_pdf
-from .serializers import (
-    GroupSerializer,
-    UserFullSerializer,
-    UserShortSerializer,
-)
+from .serializers import GroupSerializer, UserFullSerializer
 
 
 # Viewsets for the REST API
@@ -32,13 +29,16 @@ class UserViewSet(ModelViewSet):
     There are the following views: metadata, list, retrieve, create,
     partial_update, update, destroy and reset_password.
     """
+    access_permissions = UserAccessPermissions()
     queryset = User.objects.all()
 
     def check_view_permissions(self):
         """
         Returns True if the user has required permissions.
         """
-        if self.action in ('metadata', 'list', 'retrieve', 'update', 'partial_update'):
+        if self.action == 'retrieve':
+            result = self.get_access_permissions().can_retrieve(self.request.user)
+        elif self.action in ('metadata', 'list', 'update', 'partial_update'):
             result = self.request.user.has_perm('users.can_see_name')
         elif self.action in ('create', 'destroy', 'reset_password'):
             result = (self.request.user.has_perm('users.can_see_name') and
@@ -50,16 +50,13 @@ class UserViewSet(ModelViewSet):
 
     def get_serializer_class(self):
         """
-        Returns different serializer classes with respect to action and user's
-        permissions.
+        Returns different serializer classes with respect to action.
         """
-        if (self.action in ('create', 'partial_update', 'update') or
-                self.request.user.has_perm('users.can_see_extra_data')):
-            # Return the UserFullSerializer for edit requests or for
-            # list/retrieve requests of users with more permissions.
+        if self.action in ('create', 'partial_update', 'update'):
+            # Return the UserFullSerializer for edit requests.
             serializer_class = UserFullSerializer
         else:
-            serializer_class = UserShortSerializer
+            serializer_class = super().get_serializer_class()
         return serializer_class
 
     def list(self, request, *args, **kwargs):
@@ -78,6 +75,7 @@ class UserViewSet(ModelViewSet):
 
         Hides the default_password for non admins.
         """
+        #TODO: Hide default_password also in case of autoupdate.
         response = super().retrieve(request, *args, **kwargs)
         self.extract_default_password(response)
         return response
diff --git a/openslides/utils/access_permissions.py b/openslides/utils/access_permissions.py
new file mode 100644
index 000000000..844be9970
--- /dev/null
+++ b/openslides/utils/access_permissions.py
@@ -0,0 +1,30 @@
+class BaseAccessPermissions:
+    """
+    Base access permissions container.
+    """
+    def can_retrieve(self, user):
+        """
+        Returns True if the user has read access model instances.
+        """
+        return False
+
+    def get_serializer_class(self, user):
+        """
+        Returns different serializer classes according to users permissions.
+        """
+        raise NotImplementedError(
+            "You have to add the classmethod 'get_serializer_class' to your "
+            "access permissions class.".format(self))
+
+    def get_serialized_data(self, instance, user):
+        """
+        Returns the serialized data for the instance prepared for the user.
+
+        Returns None if the user has no read access.
+        """
+        if self.can_retrieve(user):
+            serializer_class = self.get_serializer_class(user)
+            data = serializer_class(instance).data
+        else:
+            data = None
+        return data
diff --git a/openslides/utils/autoupdate.py b/openslides/utils/autoupdate.py
index d530bf590..9278bf424 100644
--- a/openslides/utils/autoupdate.py
+++ b/openslides/utils/autoupdate.py
@@ -1,15 +1,12 @@
-import json
 import os
 import posixpath
+from importlib import import_module
 from urllib.parse import unquote
+
 from django.conf import settings
-from openslides.users.auth import get_user
 from django.core.wsgi import get_wsgi_application
-from django.utils.importlib import import_module
 from sockjs.tornado import SockJSConnection, SockJSRouter
-from tornado.httpclient import AsyncHTTPClient, HTTPRequest
 from tornado.httpserver import HTTPServer
-from tornado.httputil import HTTPHeaders
 from tornado.ioloop import IOLoop
 from tornado.options import parse_command_line
 from tornado.web import (
@@ -19,7 +16,8 @@ from tornado.web import (
     StaticFileHandler,
 )
 from tornado.wsgi import WSGIContainer
-from .rest_api import get_collection_and_id_from_url
+
+from openslides.users.auth import AnonymousUser, get_user
 
 RUNNING_HOST = None
 RUNNING_PORT = None
@@ -59,9 +57,6 @@ class DjangoStaticFileHandler(StaticFileHandler):
         return absolute_path
 
 
-class FakeRequest:
-    pass
-
 class OpenSlidesSockJSConnection(SockJSConnection):
     """
     SockJS connection for OpenSlides.
@@ -80,36 +75,29 @@ class OpenSlidesSockJSConnection(SockJSConnection):
         """
         Sends an OpenSlides object to all connected clients (waiters).
         """
-        # Send out internal HTTP request to get data from the REST api.
         for waiter in cls.waiters:
-            # Read waiter's former cookies and parse session cookie to new header object.
-            headers = HTTPHeaders()
+            # Read waiter's former cookies and parse session cookie to get user instance.
             try:
                 session_cookie = waiter.connection_info.cookies[settings.SESSION_COOKIE_NAME]
+            except KeyError:
+                # There is no session cookie so use anonymous user here.
+                user = AnonymousUser()
+            else:
+                # Get session from session store and use it to retrieve the user.
                 engine = import_module(settings.SESSION_ENGINE)
-                session = engine.SessionStore(session_cookie)
-
-                request = FakeRequest()
-                request.session = session
-
-                user = get_user(request)
-                serializer_class = instance.access_permissions.get_serializer_class(user)
-                serialized_instance_data = serializer_class(instance).data
-
+                session = engine.SessionStore(session_cookie.value)
+                fake_request = type('FakeRequest', (), {})()
+                fake_request.session = session
+                user = get_user(fake_request)
+            # Fetch serialized data and send them out to the waiter (client).
+            serialized_instance_data = instance.get_access_permissions().get_serialized_data(instance, user)
+            if serialized_instance_data is not None:
                 data = {
-                    'url': "foobar",
-                    'status_code': 404 if is_delete else 200,
-                    'collection': instance.get_collection_name(),
-                    'id': instance.id,
+                    'status_code': 404 if is_delete else 200,  # TODO: Refactor this. Use strings like 'change' or 'delete'.
+                    'collection': instance.get_collection_string(),
+                    'id': instance.get_rest_pk(),
                     'data': serialized_instance_data}
                 waiter.send(data)
-            except KeyError:
-                # There is no session cookie
-                pass
-            else:
-                headers.add('Cookie', '%s=%s' % (settings.SESSION_COOKIE_NAME, session_cookie.value))
-
-
 
 
 def run_tornado(addr, port, *args, **kwargs):
@@ -152,22 +140,28 @@ def inform_changed_data(is_delete, *args):
     """
     Informs all users about changed data.
 
-    The arguments are Django/OpenSlides models.
+    The first argument is whether the object or the objects are deleted.
+    The other arguments are the changed or deleted Django/OpenSlides model
+    instances.
     """
-    root_instances = set()
-    for instance in args:
-        try:
-            root_instances.add(instance.get_root_rest_element())
-        except AttributeError:
-            # Instance has no method get_root_rest_url. Just skip it.
-            pass
-
     if settings.USE_TORNADO_AS_WSGI_SERVER:
-        for root_instance in root_instances:
-            OpenSlidesSockJSConnection.send_object(root_instance, is_delete)
+        for instance in args:
+            try:
+                root_instance = instance.get_root_rest_element()
+            except AttributeError:
+                # Instance has no method get_root_rest_element. Just skip it.
+                pass
+            else:
+                if is_delete and instance == root_instance:
+                    # A root instance is deleted.
+                    OpenSlidesSockJSConnection.send_object(root_instance, is_delete)
+                else:
+                    # A non root instance is deleted or any instance is just changed.
+                    root_instance.refresh_from_db()
+                    OpenSlidesSockJSConnection.send_object(root_instance, False)
     else:
         pass
-        # TODO: Implement big varainte with Apache or Nginx as wsgi webserver.
+        # TODO: Implement big variant with Apache or Nginx as WSGI webserver.
 
 
 def inform_changed_data_receiver(sender, instance, **kwargs):
diff --git a/openslides/utils/models.py b/openslides/utils/models.py
index bc7d0f0ea..127da3eb2 100644
--- a/openslides/utils/models.py
+++ b/openslides/utils/models.py
@@ -1,4 +1,3 @@
-from django.core.urlresolvers import reverse
 from django.db import models
 
 
@@ -19,15 +18,11 @@ class MinMaxIntegerField(models.IntegerField):
 
 class RESTModelMixin:
     """
-    Mixin for django models which are used in our rest api.
+    Mixin for Django models which are used in our REST API.
     """
 
     access_permissions = None
 
-    @classmethod
-    def get_collection_name(cls):
-        return "{0}/{1}".format(cls._meta.app_label.lower(), cls._meta.object_name.lower())
-
     def get_root_rest_element(self):
         """
         Returns the root rest instance.
@@ -36,20 +31,25 @@ class RESTModelMixin:
         """
         return self
 
-    def get_root_rest_url(self):
+    def get_access_permissions(self):
         """
-        Returns the detail url of the root model of this object.
+        Returns a container to handle access permissions for this model and
+        its corresponding viewset.
         """
-        # Gets the default url-name in the same way as django rest framework
-        # does in relations.HyperlinkedModelSerializer
-        root_instance = self.get_root_rest_element()
-        rest_url = '%s-detail' % type(root_instance)._meta.object_name.lower()
-        return reverse(rest_url, args=[str(root_instance.pk)])
+        return self.access_permissions
 
-    def get_collection_string(self):
+    @classmethod
+    def get_collection_string(cls):
         """
-        Returns the string representing the name of the collection.
+        Returns the string representing the name of the collection. Returns
+        None if this is not a so called root rest instance.
         """
-        # TODO: find a way not to use the url. See #1791
-        from .rest_api import get_collection_and_id_from_url
-        return get_collection_and_id_from_url(self.get_root_rest_url())[0]
+        # TODO Check if this is a root rest element class and return None if not.
+        return '/'.join((cls._meta.app_label.lower(), cls._meta.object_name.lower()))
+
+    def get_rest_pk(self):
+        """
+        Returns the primary key used in the REST API. By default this is
+        the database pk.
+        """
+        return self.pk
diff --git a/openslides/utils/rest_api.py b/openslides/utils/rest_api.py
index 58d587bfd..596bc0e8f 100644
--- a/openslides/utils/rest_api.py
+++ b/openslides/utils/rest_api.py
@@ -101,20 +101,17 @@ class PermissionMixin:
 
     The methods check_view_permissions or check_projector_requirements are
     evaluated. If both return False self.permission_denied() is called.
-    Django REST framework's permission system is disabled.
-    """
+    Django REST Framework's permission system is disabled.
 
-    def get_serializer_class(self):
-        """
-        TODO
-        """
-        serializer_class = self.access_permissions.get_serializer_class(self.request.user) if self.access_permissions is not None else None
-        return super().get_serializer_class() if serializer_class is None else serializer_class
+    Also connects container to handle access permissions for model and
+    viewset.
+    """
+    access_permissions = None
 
     def get_permissions(self):
         """
-        Overriden method to check view and projector permissions. Returns an
-        empty interable so Django REST framework won't do any other
+        Overridden method to check view and projector permissions. Returns an
+        empty iterable so Django REST framework won't do any other
         permission checks by evaluating Django REST framework style permission
         classes  and the request passes.
         """
@@ -126,6 +123,8 @@ class PermissionMixin:
         """
         Override this and return True if the requesting user should be able to
         get access to your view.
+
+        Use access permissions container for retrieve requests.
         """
         return False
 
@@ -144,6 +143,24 @@ class PermissionMixin:
                     break
         return result
 
+    def get_access_permissions(self):
+        """
+        Returns a container to handle access permissions for this viewset and
+        its corresponding model.
+        """
+        return self.access_permissions
+
+    def get_serializer_class(self):
+        """
+        Overridden method to return the serializer class given by the
+        access permissions container.
+        """
+        if self.get_access_permissions() is not None:
+            serializer_class = self.get_access_permissions().get_serializer_class(self.request.user)
+        else:
+            serializer_class = super().get_serializer_class()
+        return serializer_class
+
 
 class ModelSerializer(_ModelSerializer):
     """
@@ -172,7 +189,7 @@ class GenericViewSet(PermissionMixin, _GenericViewSet):
 
 
 class ModelViewSet(PermissionMixin, _ModelViewSet):
-    access_permissions = None
+    pass
 
 
 class ReadOnlyModelViewSet(PermissionMixin, _ReadOnlyModelViewSet):
@@ -183,12 +200,13 @@ class ViewSet(PermissionMixin, _ViewSet):
     pass
 
 
+#TODO: Remove this method
 def get_collection_and_id_from_url(url):
     """
     Helper function. Returns a tuple containing the collection name and the id
     extracted out of the given REST api URL.
 
-    For example get_collection_and_id_from_url('http://localhost/api/users/user/3/')
+    For example get_collection_and_id_from_url('http://localhost/rest/users/user/3/')
     returns ('users/user', '3').
 
     Raises OpenSlidesError if the URL is invalid.
@@ -196,5 +214,5 @@ def get_collection_and_id_from_url(url):
     path = urlparse(url).path
     match = re.match(r'^/rest/(?P<collection>[-\w]+/[-\w]+)/(?P<id>[-\w]+)/$', path)
     if not match:
-        raise OpenSlidesError('Invalid REST api URL: %s' % url)
+        raise OpenSlidesError('Invalid REST API URL: %s' % url)
     return match.group('collection'), match.group('id')
diff --git a/openslides/utils/utils.py b/openslides/utils/utils.py
index 620083636..b2d01f01e 100644
--- a/openslides/utils/utils.py
+++ b/openslides/utils/utils.py
@@ -10,7 +10,3 @@ def to_roman(number):
         return roman.toRoman(number)
     except (roman.NotIntegerError, roman.OutOfRangeError):
         return None
-
-
-def collection_name(model_class):
-    return "{1}/{2}".format(model_class.Meta.app_label.lower(), model_class.Meta.object_name)