Notice tin containing very little (4)
I believe the answer is:
sign
'notice' is the definition.
(I've seen this before)
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for sign that I've seen before include "Endorse" , "Public notice; Leo, say" , "Omen or indication" , "Indication; symbol" , "Mark" .)