quota_over_flag examples?

[E.B.]

> > > Anyone knows how to use this flag with postfix *making postfix send
> > > special reject* "user over quota" note instead of plain SMTP reject??
> > > Is an additional database lookup (restriction class?) unavoidable? :(
> >
> > I don't actually use this, but try perhaps:
> > https://sys4.de/en/blog/2013/04/08/postfix-dovecot-mailbox-quota/
> > And perhaps search the mailing list for "quota-status" for more info.
> 
> That's not the same. Strange but I never found quota-status docs on
> Dovecot wiki nowhere!    Anyway, I think quota_over_flag is new and
> possibly Timo replacing quota-status with this flag now?

Can anyone confirm this is true?