What does SISI stand for?

Short Increment Sensitivity Index - Medicine

S I Technologies - NASDAQ symbol

SI Technologies, Inc. - NASDAQ symbol (SAG)

Southern Institute of Science and Industry (SAUS)

Staffordshire Iron and Steel Institute (SAUS)

Structural Instrumentation, Inc. - NASDAQ symbol (SAG)

Surveillance and In-Service Inspection - Nuclear energy (NRCH)