DNS Bind zone file configuration

This is a consecutive article of DNS forward and delegate - Shammerism, about zone file location, not zone file itself.
This file includes authority domain and type, it is a master or slave, and forwarder. The forwarder in this section is defined as a forwarder for specific domain. Here is a example. In generally, the file for lookup and the file for reverse lookup are required at least.

Master file should be included a db file location like below.

zone "examples.xyz" { 
    type master; 
    file "/etc/bind/db.examples.xyz"; 
    forwarders {}; 
}; 

zone "1.168.192.in-addr.arpa" { 
    type master; 
    file "/etc/bind/db.192.168.1"; 
    forwarders {}; 
};

Slave file doesn't include file directive, but should have master points like below.

zone "examples.xyz" { 
        type slave; 
        masters { 
            9.9.9.99; 
        }; 
}; 

zone "1.168.192.in-addr.arpa" { 
        type slave; 
        masters { 
            9.9.9.99; 
        }; 
};