diff --git a/chrono/api/views.py b/chrono/api/views.py
index 60ca4a1a..30d5577f 100644
--- a/chrono/api/views.py
+++ b/chrono/api/views.py
@@ -306,10 +306,10 @@ class SlotSerializer(serializers.Serializer):
     '''
     payload to fill one slot. The slot (event id) is in the URL.
     '''
-    label = serializers.CharField(max_length=250, allow_blank=True) #, required=False)
-    user_name = serializers.CharField(max_length=250, allow_blank=True) #, required=False)
-    backoffice_url = serializers.URLField(allow_blank=True) # , required=False)
-    count = serializers.IntegerField(min_value=1) # , required=False)
+    label = serializers.CharField(max_length=250, allow_blank=True)
+    user_name = serializers.CharField(max_length=250, allow_blank=True)
+    backoffice_url = serializers.URLField(allow_blank=True)
+    count = serializers.IntegerField(min_value=1)
 
 
 class SlotsSerializer(SlotSerializer):