SIDPERS
SIDS
SIE
SIF
SIGINT
Signal-to-Noise Ratio (S/N) (SNR)
Signals Security (SIGSEC)
Signature
Signature Histories
SIGSEC
SIIPT
SIL
SIM
SIMM
Simple Security Condition
| SIMS
simulation
Simulator
SINCGARS
Single Integrated Operational Plan (SIOP)
Single-Level Device
Singlet
SIOP
SIP
SIPM
SIPRI
SIPRNET
SIPT
SIR
sire
|