| Abbreviation | Definition |
|---|---|
| NIOSCERTIFICATE | 10+2 ITI puc equivalent |
| NIP | Notice, Imagine, Prevent |
| NIPAS | Northern IL Police Alarm System |
| NIPAS | Northern Illinois Police Alarm System |
| NIREP | Nuclear Industry Road Emergency Plan |
| NIS | National Identification Service |
| NIS | Non Investigative Subject |
| NIS | Nothing Is Safe |
| NJG | New Jersey Goons |
| NJPD | New Jersey Police Department |
| NJSP | New Jersey State Police |
| NK | Night Killer |
| NKA | No Known Alias |
| NL | Non-Lethal |
| NLPD | New London Police Department |
| NLPD | Non Libertarian Police Department |
| NLPD | North Liberty Police Department |
| NMDO | "Nicht mit Deiner Oma" is a prevention campaign of German City of Oberhausen Police Depart |
| NMIS | National Management Information Systems |
| NMPD | New Martinsville Police Department |