Remarkable message (6)
I believe the answer is:
signal
I believe this clue is a double definition.
'remarkable' is the first definition.
(signal can mean striking or noteworthy)
'message' is the second definition.
(I've seen this before)
(Other definitions for signal that I've seen before include "(Railway) indicator" , "Nonverbal action or gesture that encodes a message" , "Extraordinary" , "Gesture, motion" , "intimation" .)