Token clue (4)
I believe the answer is:
sign
I believe this clue is a double definition.
'token' is the first definition.
(I've seen this before)
'clue' is the second definition.
(sign is a kind of clue)
(Other definitions for sign that I've seen before include "Public notice; Leo, say" , "Augury" , "Evidence" , "Indicator" , "Signal, gesture" .)