Countermark

https://rpc.ashmus.ox.ac.uk/countermark/694 
GIC 568
ΤΟΝΖΟΥ
rectangular 
13 x 3 mm 
The Tonzos was a river in Thrace. Its personification appeared on the coins of Hadrianopolis. The countermark might have been applied there to "validate" the coins of other cities, but it is not certain 

Coins with this countermark

Number Image TypeNumber CoinNumber VolumeNumber
RPC II, 628 Show 628 17 2
RPC III, 1154 Show 1154 7 3
RPC III, 1160 Show 1160 3 3
RPC III, 1154 Show 1154 12 3
RPC III, 1124 Show 1124 2 3
RPC III, 1148E Show 1148 3 3
RPC III, 1047 Show 1047 3 3
RPC III, 1154 Show 1154 15 3
Show 103
Show 147
Show 141
RPC III, 1606A Show 1606 1 3
RPC I, 1732 Show 1732 7 1
Show 244
RPC III, 1148 Show 1148 2 3
Show 430
RPC II, 645 Show 645 4 2
RPC III, 1142 Show 1142 12 3
RPC III, 1148 Show 1148 3 3
RPC III, 1148 Show 1148 4 3
RPC III, 1103 Show 1103 5 3
RPC III, 1158 Show 1158 3 3
RPC III, 1148 Show 1148 5 3
RPC III, 1611 Show 1611 3 3
RPC III, 1148F Show 1148 1 3