Electricity transmission system in Great Britain (GB), and National Grid Gas plc (NGG) is the SO for the gas transportation system. This document and the supplementary appendices document set out our initial proposals for SO incentive schemes for NGET and NGG to apply from 1 April 2007. This document invites feedback from interested parties on a number of questions set out in it. Following consideration of respondents' views and market conditions we will develop our final proposals including statutory licence consultations for the incentive schemes.