Watch List notes:

Constantine I. A.D. 307/10-337. silvered AE centenionalis (20.05 mm, 3.35 g, 7 h). Siscia Mint, struck A.D. 320. CONSTAN-TINVS AVG, laureate head of Constantine I right / CONSTANTINVS AVGVSTI; VOT / IS / XX, concentric legend around Vota dedication in three lines // · BSIS ·. RIC 140. EF / VF, Bold portrait in somewhat unusual style, ~ 50% AR remaining on obverse; reverse slightly off-center to east, weakening right half of concentric legend. 

This type with this concentric legend only known from Siscia