12 C.F.R. § 1202.6
If FHFA determines that your request does not reasonably describe the records you seek, is overly broad, unduly burdensome to process, cannot yet be processed for reasons related to fees, or lacks required information, you will be informed in writing why your request cannot be processed. You will be given 15 calendar days to modify your request to meet all requirements. This request for additional information tolls the time period for FHFA to respond to your request under § 1202.7 of this part.