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:
diff --git a/vim b/vim
new file mode 100644
index 0000000..930386b
--- /dev/null
+++ b/vim
@@ -0,0 +1,56 @@
+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: