diff --git a/pushserver/models/cassandra.py b/pushserver/models/cassandra.py
index 896a560..472daad 100644
--- a/pushserver/models/cassandra.py
+++ b/pushserver/models/cassandra.py
@@ -1,21 +1,26 @@
 from cassandra.cqlengine import columns
 from cassandra.cqlengine.models import Model
 
 
 class PushTokens(Model):
     __table_name__ = 'push_tokens_tester'
     username         = columns.Text(partition_key=True)
     domain           = columns.Text(partition_key=True)
     device_id        = columns.Text(primary_key=True)
     app_id           = columns.Text(primary_key=True)
     background_token = columns.Text(required=False)
     device_token     = columns.Text()
     platform         = columns.Text()
     silent           = columns.Text()
     user_agent       = columns.Text(required=False)
 
 
 class OpenSips(Model):
+    """Useful for servers that need to take routing
+    decisions based on the fact that the user has push
+    tokens, without having to send push notifications
+    """
+
     __table_name__ = 'mobile_devices'
     opensipskey = columns.Text(primary_key=True)
     opensipsval = columns.Text()