This bust type is not listed in RIC with the obverse legend, but it is in Bastien.
Diocletian
A.D. 290- 291
Ӕ Antoninianus
24mm 3.9gm
IMP DIOCLETIANVS AVG; radiate helmeted and cuirassed bust left with spear and shield.
IOVI AVGG; Jupiter standing left, holding victory and leaning on long sceptre, eagle at feet.
In ex. A
RIC V Lyons 28 var.; Bastien 318
