Code of Federal Regulations Title 36. Parks, Forests, and Public Property § 36.1275.50 Restriction of materials of general historical significance unrelated to abuses of governmental power

(i) Interfere with enforcement proceedings;

(ii) Deprive a person of a right to a fair trial or an impartial adjudication;

(iii) Constitute an unwarranted invasion of personal privacy;

(iv) Disclose the identity of a confidential source who furnished information on a confidential basis, and in the case of a record compiled by a criminal law enforcement authority in the course of a criminal investigation or by an agency conducting a lawful national security intelligence investigation, confidential information furnished by a confidential source;

(v) Disclose techniques and procedures for law enforcement investigations or prosecutions, or disclose guidelines for law enforcement investigations or prosecutions if such disclosure could reasonably be expected to risk circumvention of the law;  or

(vi) Endanger the life or physical safety of any individual.