Dictionary quota with Flat file database

[Sam]

Hello,

I want specific quotas for certain users and I looking for doing that 
with dictionary quota backend and Flat file.

Because I am using "active directory" with PAM for authenticate, I can't 
get per-user quota limits with set/override them by returning 
"quota_rule" extra field from userdb.

I started reading http://wiki1.dovecot.org/Quota/Dict, saw some good 
stuff...

The problem is that I don't understand how to set the limit in the users 
files.

If I open one created file I only see the current number of messages and 
the actual size. Not the quota limits...

  vi /home/vmail/john.doe/Maildir/dovecot-quota :
priv/quota/messages
13
priv/quota/storage
600201

Here is /etc/dovecot/conf.d/90-quota.conf file details :
plugin {
# I think I have to set the default limits here
  quota_rule = *:storage=10G:messages=10000
}
...
plugin {
   quota = dict:user::file:%h/Maildir/dovecot-quota
# same result with :
# quota = dict:User::file:%h/Maildir/dovecot-quota
}

my server : CentOS Linux release 7.2.1511
dovecot : dovecot-2.2.10-5.el7.x86_64

Thanks for helping.
Sam