diff --git a/lib/lists/notifications_list.dart b/lib/lists/notifications_list.dart
index f0d4ff1..f0ef100 100644
--- a/lib/lists/notifications_list.dart
+++ b/lib/lists/notifications_list.dart
@@ -5,4 +5,45 @@ import 'package:comunic/models/notification.dart';
 ///
 /// @author Pierre HUBERT
 
-class NotificationsList extends AbstractList<Notification> {}
+class NotificationsList extends AbstractList<Notification> {
+  /// Get the ID of all the users related to the notifications
+  /// included in the list
+  List<int> get usersIds {
+    final list = List<int>();
+
+    forEach((n) {
+      if (!list.contains(n.fromUser)) list.add(n.fromUser);
+
+      if (n.onElemType == NotificationElementType.FRIENDSHIP_REQUEST ||
+          n.onElemType == NotificationElementType.USER_PAGE) {
+        if (!list.contains(n.onElemId)) list.add(n.onElemId);
+      }
+
+      if (n.fromContainerType == NotificationElementType.FRIENDSHIP_REQUEST ||
+          n.fromContainerType == NotificationElementType.USER_PAGE) {
+        if (!list.contains(n.fromContainerId)) list.add(n.fromContainerId);
+      }
+    });
+
+    return list;
+  }
+
+  /// Get the ID of all the groups related to the notifications
+  /// included in the list
+  List<int> get groupsIds {
+    final list = List<int>();
+
+    forEach((n) {
+      if (n.onElemType == NotificationElementType.GROUP_PAGE &&
+          !list.contains(n.onElemId)) list.add(n.onElemId);
+
+      if (n.fromContainerType == NotificationElementType.GROUP_PAGE &&
+          !list.contains(n.fromContainerId)) list.add(n.fromContainerId);
+
+      if (n.onElemType == NotificationElementType.GROUP_MEMBERSHIP &&
+          !list.contains(n.onElemId)) list.add(n.onElemId);
+    });
+
+    return list;
+  }
+}