
...the dark matter SIGNAL found
in sodium-iodide crystals by the Italians.
The Big Bang Theory Season 2, Episode 15

The SIGNAL for the attack
will be a bonfire.
Game of Thrones Season 4, Episode 1

And we can just send up
a SIGNAL flare.
Breaking Bad Season 2, Episode 9

How will we see your SIGNAL?
Game of Thrones Season 3, Episode 3

...this will register it
and send a SIGNAL to the laptop.
The Big Bang Theory Season 1, Episode 11