43 CFR § 2.29
When will the bureau not notify a submitter of a request for their possibly confidential information?
June 11, 2020
The notice requirements of §2.28 of this subpart will not apply if:
(a) The information has been lawfully published or officially made available to the public;
(b) Disclosure of the information is required or prohibited by a statute other than the FOIA or by a regulation (other than this part) issued in accordance with the requirements of Executive Order 12600; or
(c) The bureau has exercised due diligence to notify the submitter, but its efforts were unsuccessful.
[77 FR 76906, Dec. 31, 2012, as amended at 84 FR 61828, Nov. 14, 201]