The "Six Unifications" refer to unified specifications for protection device functionality, circuit design, terminal layout, interface standards, panel configurations, and protection settings (report formats) issued by the State Grid Corporation. This handbook covers the code of practice in protection circuitry including standard lead and device numbers, mode of connections at terminal strips, colour codes in multicore cables, dos and donts in execution. They are intended to quickly identify a fault and isolate it so the balance of the system continue to run under normal conditions. Eng, IEEE Life Fellow IEEE/IAS/I&CPSD Protection & Coordination WG Chair Jacobs Canada, Calgary, AB rasheek.