Under the National Incident Management System (NIMS), use of acronyms is supposed to be avoided, because they vary between agencies and can be unclear. Instead, people are told to just speak plainly.
FEMA still has a ways to go on that. These are from FEMA documents:
"... After-Action Report (AAR) for the Top Officials (TOPOFF) 4 Full-Scale Exercise (FSE) ... composed at the After-Action Conference (AAC) ...
"TOPOFF 4 (T4) - The T4 FSE used a radiological dispersal device (RDD) scenario based on National Planning Scenario (NPS) ... As observed in T3 ... departments and agencies (D/As) ...
