(a) Except as outlined in Sec. 2.29 of this subpart, a bureau must promptly notify a submitter in writing when it receives a FOIA request if either:
(1) The requested information has been designated in good faith by the submitter as information considered protected from disclosure under Exemption 4 of the FOIA, found at 5 U.S.C. 552(b)(4); or
(2) The bureau believes that requested information may be protected from disclosure under Exemption 4.
(b) If a large number of submitters are involved, the bureau may publish a notice in a manner reasonably calculated to reach the attention of the submitters (for example, in newspapers or newsletters, the bureau's Web site, or the Federal Register) instead of providing a written notice to each submitter.