ADRs

American Depositary Receipts, negotiable certificates representing holdings in ADSs.

ADSs

American Depositary Shares, each of which represents the right to receive five ordinary shares.

AGM

Annual General Meeting.

bcm

Billion cubic metres.

Company or National Grid Transco

National Grid Transco plc.

Corporate Centre

Core Group functions operating from the Group’s head office.

DC

Direct current.

Demerger

The demerger of Lattice from BG Group plc which became effective on 23 October 2000.

EMFs

The electric and magnetic fields produced by all electrical equipment and appliances.

FERC

Federal Energy Regulatory Commission.

GAAP

Generally accepted accounting principles.

GridAmerica

The Group’s business that manages electricity transmission operations for other utilities in the US.

Gridcom

The Group’s communications infrastructure business.

Group

National Grid Transco and/or its subsidiary undertakings or any of them as the context requires.

GW

Gigawatt, 10⁹ watts.

GWh

Gigawatt hours.

HSE

Health and Safety Executive.

kV

Kilovolt, 10³ volts.

kW

Kilowatt, 10³ watts.

kWh

Kilowatt hours.

Lattice or Lattice Group

Lattice Group plc and/or its subsidiary undertakings or any of them as the context requires immediately prior to the completion of the Merger.

LNG

Liquefied natural gas.

LTI

Lost Time Injury. A work-related injury that caused the person to be away from work for at least one normal shift after the shift on which the injury occurred, because he/she is unfit to perform his/her duties.

mcm

Million cubic metres.

Merger

The merger of Lattice and National Grid which became effective on 21 October 2002.

MJ/cuM

Megajoules per cubic metre.

MW

Megawatt, 10⁶ watts.

MWh

Megawatt hours.

National Grid or National Grid Group

National Grid Group plc and/or its subsidiary undertakings or any of them as the context requires immediately prior to the completion of the Merger.

National Grid Company or NGC

National Grid Company plc.

National Grid Transco or the Company

National Grid Transco plc.

National Grid USA

The holding company which owns the Group’s electricity, gas and other interests in the US.

Niagara Mohawk

Niagara Mohawk Holdings Inc., the US utility acquired by National Grid on 31 January 2002.

NTS or National Transmission System

The UK national gas transmission system owned and operated by Transco.

Ofgem

The Office of Gas and Electricity Markets which on 16 June 1999 became the new name for the combined Office of Electricity Regulation and Office of Gas Supply.

ordinary shares

Ordinary shares of 10 pence each in the capital of National Grid Transco.

pence or p

United Kingdom (UK) currency.

pound(s) sterling or £

United Kingdom (UK) currency.

PUHCA

Public Utility Holding Company Act of 1935.

SEC

United States Securities and Exchange Commission.

tonnes CO₂ equivalent

Measure of greenhouse gas emissions in relation to the impact of carbon dioxide.

TW

Terawatt, 10¹² watts.

TWh

Terawatt hours.

Transco

Transco plc.

US dollars, US$ or $

United States (US) currency.