Reconnaissance Scout Signal

A reconnaissance scout signal was a signal sent by a reconnaissance scout.

The Thirteenth Doctor was aware that the Reconnaissance Dalek, following its reconstruction, lacked the ability to summon the Dalek invasion fleet. As such, it commandeered the resources of the GCHQ in an attempt to do so only to be thwarted by the Doctor. (TV: Resolution)

A ship of Death Squad Daleks would listen for it, and travel to the origin of the signal using the Time Vortex. The Doctor summoned Death Squad Daleks to Earth using this signal in order to rid the Earth of Defence Drones that had gone rogue with impure Kaled mutants inside them. (TV: Revolution of the Daleks)