host & service _notification_options default value vs readthedocs

[gst]

Not an issue but more a question first (which could lead to an issue) :

In http://shinken.readthedocs.org/en/latest/08_configobjects/contact.html?highlight=notification_options we have :

host_notification_options
This directive is used to define the host states for which notifications can be sent out to this contact. 
Valid options are a combination of one or more of the following:

d = notify on DOWN host states
u = notify on UNREACHABLE host states
r = notify on host recoveries (UP states)
f = notify when the host starts and stops flapping,
s = send notifications when host or service scheduled downtime starts and ends. 
If you specify n (none) as an option, the contact will not receive any type of host notifications.

service_notification_options
This directive is used to define the service states for which notifications can be sent out to this contact. 
Valid options are a combination of one or more of the following:

w = notify on WARNING service states
u = notify on UNKNOWN service states
c = notify on CRITICAL service states
r = notify on service recoveries (OK states)
f = notify when the service starts and stops flapping.
n = (none) : the contact will not receive any type of service notifications.

Already, what if someone put "n" with others (valid) "flags" for both options ??
should/will "n" always take precedence ?

but the actual (default) value if you don't set one of the 2 attributes/properties on a contact is :

[ "" ]

That is a list with an empty string. This comes, I guess, from the default declared in Contact for these 2 properties :

'host_notification_options': ListProp(default=[''], fill_brok=['full_status'],
                                                         split_on_coma=True),
'service_notification_options': ListProp(default=[''], fill_brok=['full_status'],
                                                              split_on_coma=True),

shouldn't that default more consistently be ['n'] instead of [''] (or any other valid combination of the possible flags) ?