Countermark

https://rpc.ashmus.ox.ac.uk/countermark/1367 
GIC
uncertain monogram, ΤΥΡ?
incuse 
the two examples applied to coins of Laodicea Catacecaumene. If ΤΥΡ it could stand for Tyriaeum, a city close to Laodicea Catacecaumene, which never struck coins 

Coins with this countermark

Number Image TypeNumber CoinNumber VolumeNumber
RPC II, 1612 Show 1612 19 2
Show 60