Comment 1 for bug 1056637

the right ones should be:
# ============ Notification System Options =====================

# Notifications can be sent when network/subnet/port are create, updated or deleted.
# There are three methods of sending notifications: logging (via the
# log_file directive), rpc (via a message queue) and
# noop (no notifications sent, the default)

# Notification_driver can be defined multiple times
# Do nothing driver
# notification_driver = quantum.openstack.common.notifier.no_op_notifier
# Logging driver
# notification_driver = quantum.openstack.common.notifier.log_notifier
# RPC driver
# notification_driver = quantum.openstack.common.notifier.rabbit_notifier

# default_notification_level is used to form actual topic names or to set logging level
# default_notification_level = INFO

# default_publisher_id is a part of the notification payload
# host = myhost.com
# default_publisher_id = $host

# Defined in rabbit_notifier for rpc way, can be comma separated values.
# The actual topic names will be %s.%(default_notification_level)s
# notification_topics = notifications