Countermark

https://rpc.ashmus.ox.ac.uk/countermark/1551 
GIC 786 i
denominational mark Δ
incuse 
5 x 5 mm 
Applied at the same time as GIC 754 (Β ο). Callu suggested that the o stood for obols (he assumed 1 obol = 2 assaria). Sometimes on reverse. J Johnston (p. 217) suggested that the Δ 'appears to be engraved on the die'. 

Coins with this countermark

Number Image TypeNumber CoinNumber VolumeNumber
RPC X, — (number not assigned), type ID 63878 Show 501 7 10
RPC X, — (number not assigned), type ID 63878 Show 501 8 10
RPC X, — (number not assigned), type ID 63878 Show 501 11 10
RPC X, — (number not assigned), type ID 63874 Show 505 6 10
RPC X, — (number not assigned), type ID 81221 Show 503 17 10
RPC X, — (number not assigned), type ID 81221 Show 503 7 10
RPC X, — (number not assigned), type ID 81221 Show 503 4 10
RPC X, — (number not assigned), type ID 81228 Show 504 4 10
RPC X, — (number not assigned), type ID 81228 Show 504 2 10
RPC X, — (number not assigned), type ID 63877 Show 502 1 10
RPC X, — (number not assigned), type ID 63877 Show 502 11 10
RPC X, — (number not assigned), type ID 63877 Show 502 14 10
RPC X, — (number not assigned), type ID 63877 Show 502 8 10
RPC X, — (number not assigned), type ID 63877 Show 502 7 10
RPC X, — (number not assigned), type ID 63877 Show 502 3 10
RPC X, — (number not assigned), type ID 63877 Show 502 2 10
RPC X, — (number not assigned), type ID 81228 Show 504 10 10
RPC X, — (number not assigned), type ID 81221 Show 503 9 10