JUDAEA, Ascalon, AE21-22 (22mm, 10.75g, 12h), dated CY 189 (85/6).
ΣΕΒΑΣTOΣ, head laureate left; ΑΣΚΑΛΩ, Tyche standing left on prow with standard and aphlaston, incense altar in left field, dove standing left in right field and ΘΠΡ/B.
RPC 2211 .
There is clearly a B in the field beneath ΘΠΡ on the reverse of this coin and on the previous coin. It also appears, but isn't mentioned, on the RPC plate coin. Other than "two" I don't know what it could mean.