Each bill passed by Congress is enrolled for Presidential action. A bill becomes law by Presidential signature. The Constitution requires the President to approve the bill by signature or to veto it by returning the bill to the house from which it originated with his objections for reconsideration. A veto is overridden with a two-thirds vote in each chamber, and the bill becomes law. Finally, a bill may become law by "pocket veto", whereby the President does not return the bill to Congress with objections within 10 days.
When a bill is passed by both houses of Congress and signed by the President, it becomes a public law, or statute. Public laws are published by the federal government in two basic formats: chronological and subject matter. The United States Statutes at Large publishes the laws chronologically; the United States Code (USC) publishes the laws by subject matter.
All public and private laws enacted each session by the United States Congress are published in chronological order by date of passage in this official version of U.S. law. Concurrent resolutions and Presidential proclamations are also included.
The United States Code (USC) is the codified form of all public, general, and permanent laws of the United States. Codification is the process by which the laws are arranged by subject matter. The complete set of the USC contains 50 titles, and is published every six years, with annual supplements issued between editions.