ECG meaning in Governmental ?

The National Security and Homeland Security Presidential Directive (National Security Presidential Directive NSPD 51/Homeland Security Presidential Directive HSPD-20, sometimes called simply "Executive Directive 51" for short), signed by President of the United States George W. Bush on May 4, 2007, is a Presidential Directive establishing a comprehensive policy on the federal government structures and operations in the event of a "catastrophic emergency". Such an emergency is defined as "any incident, regardless of location, that results in extraordinary levels of mass casualties, damage, or disruption severely affecting the U.S. population, infrastructure, environment, economy, or government functions."

The unclassified portion of the directive (which replaced President Bill Clinton's 1998 Presidential Decision Directive 67), was posted on the White House website on May 9, 2007, without any further announcement or press briefings, although Special Assistant to George W. Bush Gordon Johndroe answered several questions on the matter when asked about it by members of the press in early June 2007.