29 C.F.R. § 1401.25 – Responses to requests.

(a) In general. To the extent practicable, the FMCS will communicate electronically with requesters.
(b) Acknowledgments of requests. The FMCS will acknowledge a request in writing and assign it an individualized tracking number if it will take longer than 10 working days to process.
(c) Estimated dates of completion and interim responses. Upon request, the Agency will provide an estimated date by which it expects to provide a response to the requester. If a request involves a voluminous amount of material, or searches in multiple locations, the FMCS may provide interim responses, releasing the records on a rolling basis.
(d) Grants of requests (fees). Once the Agency determines it will grant a request in full or in part, it will notify the requester in writing. The Agency will also inform the requester of any fees charged under § 1401.30 and will disclose the requested records to the requester promptly upon payment of any applicable fees. The Agency will inform the requester of the availability of its FOIA Public Liaison to offer assistance.
(e) Adverse determinations of requests. If the Agency makes an adverse determination denying a request in any respect, it must notify the requester of that determination in writing. Adverse determinations, or denials of requests, include decisions that: The requested record is exempt, in whole or in part; the request does not reasonably describe the records sought; the information requested is not a record subject to the FOIA; the requested record does not exist, cannot be located, or has been destroyed; or the requested record is not readily reproducible in the form or format sought by the requester. Adverse determinations also include denials involving fees or fee waiver matters or denials of requests for expedited processing.
(f) Content of denial. The denial must be signed by the head of the Agency or designee and must include:
1. (1) The name and title or position of the person responsible for the denial;
2. (2) A brief statement of the reasons for the denial, including any FOIA exemption applied by the Agency in denying the request;
3. (3) An estimate of the volume of any records or information withheld, such as the number of pages or some other reasonable form of estimation, although such an estimate is not required if the volume is otherwise indicated by deletions marked on records that are disclosed in part or if providing an estimate would harm an interest protected by an applicable exemption;
4. (4) A statement that the denial may be appealed under § 1401.27, and a description of the appeal requirements; and
5. (5) A statement notifying the requester of the assistance available from the Agency's FOIA Public Liaison, and the dispute resolution services offered by Office of Government Information Services.
(g) Markings on released documents. Records disclosed in part must be marked clearly to show the amount of information redacted and the exemption under which the redaction was made unless doing so would harm an interest protected by an applicable exemption. The location of the information redacted must also be indicated on the record, if technically feasible.
(h) Use of record exclusions.
1. (1) In the event the FMCS identifies records that may be subject to exclusion from the requirements of the FOIA pursuant to 5 U.S.C. 552(c), the Agency will confer with Department of Justice, Office of Information Policy (OIP), to obtain approval to apply the exclusion.
2. (2) In the event the FMCS applies an exclusion, it will maintain an administrative record of the process of invocation and approval of the exclusion by OIP.