From the Introduction: "This reference guide is a component of the National Fire Incident Reporting System (NFIRS) Version 5.0. It provides both instructions for reporting data to NFIRS Version 5.0 and an understanding of the data elements collected by the system. It also serves as a reference for the coding of the data. NFIRS is a tool that fire departments use both to report fires and other incidents to which fire departments respond and to maintain records of these incidents in a uniform manner. NFIRS 5.0 is a modular, all-incident reporting system designed by the U.S. Fire Administration, a part of the Department of Homeland Security, with input from the fire service and other users of the data."
NFIRS 5.0 Complete Reference Guide; National Fire Incident Reporting System 5.0 Complete Reference Guide
Lessons Learned Information Sharing (LLIS)