36 C.F.R. § 1600.5 – Responses to requests.

(a) Acknowledgments of requests. On receipt of your request, the Foundation ordinarily will send an acknowledgment letter to you, which will confirm your agreement to pay fees under § 1600.3(d) and provide an assigned request number for further reference.
(b) Referral to another agency. When a requester seeks records that originated in another Federal government agency, the Foundation will refer the request to the other agency for response. If the Foundation refers the request to another agency, it will notify the requester of the referral. A request for any records classified by some other agency will be referred to that agency for response.
(c) Grants of requests. Ordinarily, the Foundation will have 20 business days from when your request is received to determine whether to grant or deny your request. Once the Foundation determines to grant a request in whole or in part, it will notify you in writing. The Foundation will inform you in the notice of any fee charged under § 1600.10 and will disclose records to you promptly on payment of any applicable fee. Records disclosed in part will be marked or annotated to show the amount of information deleted, unless doing so would harm an interest protected by an applicable exemption. The location of the information deleted also will be indicated on the record, if technically feasible.
(d) Adverse determinations of requests. If the Foundation denies your request in any respect, it will notify you of that determination in writing. Adverse determinations, or denials of requests, consist of: a determination to withhold any requested record in whole or in part; a determination that a requested record does not exist or cannot be located; a determination that a record is not readily reproducible in the form or format sought; a determination that what has been requested is not a record subject to the FOIA; a determination on any disputed fee matter, including a denial of a request for a fee waiver; and a denial of a request for expedited treatment. The denial letter shall be signed by the General Counsel or his/her designee, and shall include:
1. (1) The name and title or position of the person responsible for the denial;
2. (2) A brief statement of the reason(s) for the denial, including any FOIA exemption applied by the component in denying the request;
3. (3) An estimate of the volume of records or information withheld, in number of pages or in some other reasonable form of estimation. This estimate does not need to be provided if the volume is otherwise indicated through deletions on records disclosed in part, or if providing an estimate would harm an interest protected by an applicable exemption; and
4. (4) A statement that the denial may be appealed under § 1600.8(a) and a description of the requirements for appeal.