What does NISI stand for?

Network Information Services Infrastructure (SAUS)

Niebla siphonoloba Spjut - Scientific name - Family: Ramalinaceae - USDA National Plant Data Center symbol - Botany - Taxonomy (USDA)

Ninety Six National Historic Site - Ninety Six, SC - National Park Service designator (NPSD)

Northwest Instrument Systems, Inc. (SAUS)