ratio of service to fighting personnel

reduction ratio / gear ratio

Voltage Standing Wave Ratio (VSWR) / voltage standing-wave ratio

jam to signal ratio (J/S ratio)

fighter-to-administrative personnel ratio

servicing personnel / maintenance personnel

rescue and fire fighting service

fire fighting service

distance learning for service personnel

non-prior-service personnel

personnel service

personnel service support (PSS)

service personnel

aspect ratio

high expansion-ratio

mass ratio

power-to-weight ratio

signal-to-noise ratio (SNR; S/N)

thrust-to-weight ratio

damping ratio

attenuation ratio

base pressure ratio

weight-horsepower ratio

weight-strength ratio

depression ratio

explosion ratio

infantry-armor ratio

forward gear ratio

fuel-air ratio

fuselage fineness ratio

compression ratio

engine pressure ratio (EPR)

excess air ratio