Help with DHCP and mac class

I am new with this system leave the debian and I want to organize my network, but in my dhcp as I declare the classes

example

class “mac_deny” {
match if ( substring(hardware,1,3) = 24:0a:63 ) or
( substring(hardware,1,3) = 00:60:b0 ) or
( substring(hardware,1,3) = 00:10:83 );

class “MAC-XXX” {
match hardware;
}
subclass “MAC-INFORMATICOS” 1:90:97:f3:e9:e7:8a;
subclass “MAC-INFORMATICOS” 1:AC:AF:B9:F6:D5:68;
subclass “MAC-INFORMATICOS” 1:14:56:8e:b4:37:6e {
}

in my subnet

deny members of “MAC-XXX”;
deny members of “mac_deny”;

sample

subnet 10.192.168.0 netmask 255.255.254.0 {
interface eth1;
pool {
authoritative;
deny members of “MAC-XXX”;
deny members of “mac_deny”;
default-lease-time 300;
max-lease-time 360;
range 10.192.169.1 10.192.169.254;
option routers 10.192.168.1;
option ntp-servers 10.192.168.2;
option domain-name-servers 192.168.1.9,192.168.1.2;
option subnet-mask 255.255.254.0;
option broadcast-address 10.192.169.255;
option domain-name “NET-HCQHO”;
}
}