Voltage Levels as per IE Rules

Please define "IE".

As per IE Rules (Indian Electricity Rules 1956)

Chapter 1 Clause (av)

(av) "Voltage" means the difference of electric potential measured in volts between any two conductors or between any part of either conductor and the earth as measured by a suitable voltmeter and is said to be;

"Low" where the voltage does not exceed 250 volts under normal conditions subject, however, to the percentage variation allowed by these rules;

"Medium" where the voltage does not exceed 650 volts under normal conditions subject, however, to the percentage variation allowed by these rules;

"High" where the voltage does not exceed 33,000 volts under normal conditions subject, however, to the percentage variation allowed by these rules;

"Extra high" where the voltage exceeds 33,000 volts under normal conditions subject, however, to the percentage variation allowed by these rules.

Hope this clarifies.

I think, it is Rule (2), Clause (av).