From the earliest days of the federal government, Presidents, exercising magisterial or executive power not unlike that of a monarch, from time to time have issued directives establishing new policy, decreeing the commencement or cessation of some action, or ordaining that notice be given to some declaration. The instruments used by Presidents in these regards have come to be known by various names, and some have prescribed forms and purposes. Executive orders and proclamations are probably two of the best-known types, largely because of their long-standing use and publication in the Federal Register and the Code of Federal Regulations. Others are less familiar, some because they are cloaked in official secrecy. There is, as well, the oral presidential directive, the sense of which is captured in the announcement that records what the President has prescribed or instructed. This report provides an overview of the different kinds of directives that have primarily been utilized by twentieth-century Presidents. It also presents background on the historical development, accounting, use, and effect of such directives.