NSSE
National Special Security Event (NSSE). An event of national significance as determined by the Secretary of Homeland Security. These national or international events, occurrences, contests, activities, or meetings, which, by virtue of their profile or status, represent a significant target, and therefore warrant additional preparation, planning, and mitigation efforts. The USSS, FBI, and FEMA are the Federal agencies with lead responsibilities for NSSEs; other Federal agencies, including DoD, may provide support to the NSSE if authorized by law.
Source
32 CFR § 183.3
Scoping language
Unless otherwise noted, these terms and definitions are for the purpose of this part only.