Presidential directive  A Presidential directive, or executive action, is a written or oral instruction or declaration issued by the President of the United States, which may draw upon the powers vested in the president by the U.S. Constitution, statutory law, or, in certain cases, congressional and judicial acquiescence. Such directives, which have been issued since the earliest days of the federal government, have become known by various names, and some have prescribed forms and purposes. Presidential directives remain in effect until they are revoked, which the president is free to do. The classification of presidential directives is not easily done, as the distinction between the types can be quite arbitrary, arising from convenience and bureaucratic evolution, and none are defined in the Constitution. Furthermore, the different types may overlap. As one legal scholar put it: "it is a bit misleading to overclassify presidential directives as comprising separate and distinct 'types' just because they have different headings at the top of the first page". In terms of legal applicability, what matters is the substance of the directive, not the form, unless a certain kind of directive is specifically required by relevant statute. Presidential directives may be challenged in court or through congressional action. Congress may revoke or modify a presidential directive, directly or indirectly, but only insofar as the directive is based on congressional legislation. Direct repeal by congress is quite rare in modern times, because it may be necessary to override a presidential veto, which requires an elusive two-thirds supermajority in both chambers. Two of the oldest and best known directives are the Executive Order and the presidential proclamation. In 1907, the State Department undertook to retroactively number executive orders and presidential proclamations. The denomination of "executive order" was largely due to the fact that the first executive order they chose to number (from 1862) was titled "Executive Order Establishing a Provisional Court in Louisiana". It was an imperfect exercise, however, and many directives were missed. The Federal Register Act of 1935 required both executive orders and proclamations to be published in the "Federal Register", with few exceptions. The proper form and routing of executive orders and presidential proclamations has been governed since 1962 by , as amended. The first presidential proclamation appeared in October 1789 declaring a day of thanksgiving at the request of congress. The use of executive orders also stretches back at least to 1789. The first directive called an administrative order appeared in 1940. Subsequent directives denominated as administrative orders have taken a variety of forms, and have sometimes overlapped with other kinds of presidential directives.