What does NIU stand for?

Mato - Language code (ETLW)

NATO Interface Unit (MCD)

Naval Intelligence Unit

Navigation Interface Unit - Navy (CAAL)

Network Interface Unit - Computer science

Niue - ANSI three-letter standard code (CNC)

Niuean - GeoNet three-character language code (GEON)

Niumate - Tonga - Seismograph station code, US Geological Survey - Closed (SEIS)

North american ISDN Users (SAUS)

Northern Illinois University - Dekalb, IL

Northern Interparliamentary Union (SAUS)

University of Northern Iowa, Cedar Falls, IA - OCLC symbol (OCLC)