The Privacy Act requires each agency to publish a notice of its systems of records in the Federal Register. This is called a System of Record Notice (SORN).
Sources:
NIST SP 800-79-2
under SORN
The notice(s) published by an agency in the Federal Register upon the establishment and/or modification of a system of records describing the existence and character of the system.
Sources:
NIST SP 800-53 Rev. 5
from
OMB Circular A-108