From the Introduction: "This document provides the procedures that staff from the Department of Homeland Security's Federal Emergency Management Agency (FEMA), FEMA contractors, and other organizations that partner with FEMA are to follow for processing new and revised Flood Insurance Study (FIS) Reports, Flood Insurance Rate Maps (FIRMs), and FIRM Databases. Specifically, this document provides guidance on due process procedures afforded during the Post-Preliminary Processing (PPP) phase of a Flood Risk Project. The PPP phase is the period of the Flood Risk Project from after Preliminary Issuance to the Effective Date."
Guidance Document 56
U.S. Federal Emergency Management Agency: https://www.fema.gov/