English abbreviations from niprnet to nit
- NIPRNET (Non-Secure Internet Protocol Router Network)
- NIPS (Naval Intelligence Processing System)
- NIQ (Niaqornat Heliport)
- NIR (Northern Ireland (FIFA trigram; not eligible for an ISO 3166 or IOC trigram))
- NIRA (National Import Racing Association)
- NIRSA (National Intramural-Recreational Sports Association)
- NIRT (Nuclear Incident Response Team)
- NIS (Simberi Airport)
- NISAC (U.S. National Infrastructure Simulation and Analysis Center)
- NISCAP (NSA Information System Certification and Accreditation Program)
- NISCC (Northern Ireland Social Care Council)
- NISDA (Nantucket Island School of Design and the Arts)
- NISER (National Institute of Science Education and Research)
- NISH (Noncombatant Evacuation Operation (NEO) Intelligence Support Handbook)
- NISO (National Information Standards Organization)
- NISOD (National Instituite for Staff and Organizational Development)
- NISP (National Intelligence Support Plan)
- NISS (New Icmi Study Series)
- NIST (National Institute of Standards and Technology)
- NIT (National Invitation Tournament (U.S. college basketball))