sign - soli
- sign bit
- sign change
- sign on
- sign sound box
- sign-off
- sign-off list
- sign-on
- signal area
- signal arrival time
- signal batallion
- signal box
- signal cartridge
- signal determination
- signal enhancement
- signal generator
- signal input
- signal lamp
- signal light
- signal man
- signal mast
- signal notable victory
- signal operation
- signal party
- signal pistol
- signal processing
- signal processing unit
- signal recording
- signal rocket
- signal service
- signal summation unit
- signal-noise ratio
- signal-to-clutter ratio
- signal-to-interference ratio
- signal-to-noise ratio
- signaling methods
- signalling concensus
- signalling lamp
- signalling lights
- signalling mirror
- signalling speed
