Countermark

https://rpc.ashmus.ox.ac.uk/countermark/662 
GIC 532
ΔIO ΚΑ
rectangular 
14 x 6 mm 
Zeus Kasios - applied to (very) worn coins. It seems Corcyra produced no coins of their own from late Hellenistic until Antonine time and GIC 532 and GIC 544 likely sanctioned continued circulation 

Coins with this countermark

Number Image TypeNumber CoinNumber VolumeNumber
Show 163
Show 164
Show 165