diff --git a/communication/models.py b/communication/models.py
index 220d29d..8a89504 100644
--- a/communication/models.py
+++ b/communication/models.py
@@ -1,5 +1,4 @@
 from django.db import models
-from django.conf import settings
 from django.contrib.auth.models import Group
 from django.contrib.auth import get_user_model
 from django.contrib.contenttypes.fields import (
@@ -16,31 +15,41 @@ class Subscription(models.Model):
     object_id = models.PositiveIntegerField()
     content_object = GenericForeignKey('content_type', 'object_id')
 
+    class Meta:
+        abstract = True
+
 
 class UserSubscription(Subscription):
-    user = models.ForeignKey(settings.AUTH_USER_MODEL)
+    user = models.ForeignKey(User)
     is_unsub = models.BooleanField(
         _("désinscription"),
         default=False
     )
 
+    class Meta:
+        verbose_name = _("souscription utilisateur")
+
 
 class GroupSubscription(Subscription):
     group = models.ForeignKey(Group)
 
+    class Meta:
+        verbose_name = _("souscription en groupe")
+
 
 class SubscriptionMixin(models.Model):
     subscribed_users = GenericRelation(UserSubscription)
     subscribed_groups = GenericRelation(GroupSubscription)
 
-    def get_unique_users(self):
+    def get_manual_subscribers(self):
         return self.subscribed_users.filter(is_unsub=False)
 
-    def get_group_users(self):
+    def get_subscribers_from_groups(self):
         return User.objects.filter(group__in=self.subscribed_groups.all())
 
     def get_all_subscribers(self):
-        return (self.get_unique_users().union(self.get_group_users())
+        return (self.get_manual_subscribers()
+                    .union(self.get_subscribers_from_groups())
                     .exclude(is_unsub=True))
 
     class Meta: