31 C.F.R. § 2.22 General restrictions on access [4.1].
Title 31 - Money and Finance: Treasury
(a) Determination of Need-To-Know. Classified information shall be made available to a person only when the possessor of the classified information establishes in each instance, except as provided in section 4.3 of the Order, that access is essential to the accomplishment of official United States Government duties or contractual obligations. (b) Determination of Trustworthiness. A person is eligible for access to classified information only after a showing of trustworthiness as determined by the Secretary of the Treasury based upon appropriate investigations in accordance with applicable standards and criteria. (c) Classified Information Nondisclosure Agreement. Standard Form 312 (Classified Information Nondisclosure Agreement) or the prior SF 189, bearing the same title, are nondisclosure agreements between the United States and an individual. The execution of either the SF 312 or SF 189 agreement by an individual is necessary before the United States Government may grant the individual access to classified information. Bureaus and the Departmental Offices must retain executed copies of the SF 312 or prior SF 189 in file systems from which the agreements can be expeditiously retrieved in the event the United States must seek their enforcement. Copies or legally enforceable facsimiles of the SF 312 or SF 189 must be retained for 50 years following their date of execution. The national stock number for the SF 312 is 7540–01–280–5499.
Title 31: Money and Finance: Treasury
PART 2—NATIONAL SECURITY INFORMATION
Subpart D—Safeguarding
§ 2.22 General restrictions on access [4.1].

