The Office of Legal Counsel (OLC) assists the Attorney General of the United States in their function as legal adviser to the President and all the executive branch agencies, hence the appellation "the president's law firm." OLC drafts legal opinions of the Attorney General and also provides its own written opinions and oral advice in response to requests from the Counsel to the President, the various agencies of the executive branch, and offices within the Department of Justice. Such requests typically deal with legal issues of particular complexity and importance or about which two or more agencies are in disagreement. The Office also is responsible for providing legal advice to the executive branch on all constitutional questions and reviewing pending legislation for constitutionality.
