Answer: signalers

AnswerCrossword Clue
signalersmake or send a signal
signalerscommunicate or indicate by or as if by signals signaled the end of an era
signalersconstitute a characteristic feature of (a meaningful linguistic form)
signalersSIGNALER, one that signals (to notify by means of communication)
signalersto notify by a signal signal the fleet to turn back