The reverse of this irregular Constantine II Caesar coin (note the title NOB in the obv. legend) combines the type of the Caesares Constantine and Crispus (VOT X) with the reverse legend of their father (DN CONSTANTINI MAX AVG). The legend that accompanies the Caesares’ tenth vows on official coins is CAESARVM NOSTRORVM. The reverse prototype(s) was an Aquileia or Rome mint coin, as these were the only mints that used the palm branches in the design.
The coin above imitates a Vota type of Constantine of an unknown mint.
This imitation of a vota coin shows a typical barbarous Siscia mint mark, familiar from the abundant Laetae imitations – ISI with the S on its back. The obverse bust is laureate and holds a spear and a shield. The legend ... MOB CHFPHS seems to indicate a prototype of a Caesar.