Special access programs (SAPs) in the federal government of the United States of America are security protocols that provides highly classified information with safeguards and access restrictions that exceed those for regular (collateral) classified information. It may be a type of black project. In addition to collateral controls, a SAP may impose more stringent investigative or adjudicative requirements, specialized nondisclosure agreements, special terminology or markings, exclusion from standard contract investigations (carve-outs), and centralized billet systems.