The United States Statutes at Large, commonly referred to as the Statutes at Large and abbreviated Stat., is the official record of Acts of Congress and concurrent resolutions passed by the United States Congress. Each act and resolution of Congress is called a slip law, which is classified as either public law (abbreviated Pub.L.) or private law (Pvt.L.), and designated and numbered accordingly. At the end of a Congress session, slip laws (now commonly called session laws) are compiled into "Statutes at Large", which are numbered and organised by Congress session. They are part of a three-part model for publication of federal statutes consisting of slip laws, session laws ("Statutes at Large"), and codification ("United States Code").