The Combined Code on Corporate Governance sets out standards of good practice in relation to issues such as board composition and development, remuneration, accountability and audit and relations with shareholders.
All companies incorporated in the UK and listed on the Main Market of the London Stock Exchange are required under the Listing Rules to report on how they have applied the Combined Code in their annual report and accounts. Overseas companies listed on the Main Market are required to disclose the significant ways in which their corporate governance practices differ from those set out in the Code.
http://www.frc.org.uk/corporate/combinedcode.cfm
The June 2008 edition of the Code took effect at the same time as new FSA Corporate Governance Rules implementing EU requirements relating to corporate governance statements and audit committees.