smtpd_client_restrictions in master.cf

==== Required information ====
- iRedMail version: 0.8.3
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): MySQL
- Linux/BSD distribution name and version: FreeBSD jail
- Related log if you're reporting an issue: /var/log/maillog
====

Hello,
I would like to know purpose of this row in the /usr/local/etc/postfix/master.cf:
-o smtpd_client_restrictions=permit_mynetworks,permit_sasl_authenticated,reject

Isn't it just duplication of smtpd_client_restrictions in the postfix/main.cf?

Thanks a lot.
Jan