★ A curious spelling error ★

Diocletian, 284-305. Follis (Bronze, 27 mm, 9.67 g, 6 h), Alexandria, 304-305. IMP C DIOCLETIANVS P F AVG Laureate head of Diocletianus to right. Rev. IOVI CO-NS OAES (sic!) / S - B / P // ALE Jupiter, nude but for chlamys over his left shoulder, standing front, head to left, holding Victory on globe in his right hand and long scepter in his left. RIC 41. A sharply struck piece with a bold portrait. Very minor flan faults on the reverse, otherwise, extremely fine.

What makes this coin particularly interesting is that the die engraver erroneously spelled the title CAES as OAES on the reverse!