Martin is correct. Common enough. Your coin is attributed as follows:
Diocletian, AE Follis, Carthage, 299-303 AD. IMP DIOCLETIANVS P F AVG, laureate head right / SALVIS AVGG ET CAESS FEL KART, Carthage standing left with fruits in both hands; I in left field; A in ex. RIC VI Carthage 33a. I cannot see any letters in exergue, but I do believe I see the I in the left field. Here is the wildwinds example: http://wildwinds.com/coins/ric/dioc...RIC_033a.jpg
BTW, welcome
Diocletian, AE Follis, Carthage, 299-303 AD. IMP DIOCLETIANVS P F AVG, laureate head right / SALVIS AVGG ET CAESS FEL KART, Carthage standing left with fruits in both hands; I in left field; A in ex. RIC VI Carthage 33a. I cannot see any letters in exergue, but I do believe I see the I in the left field. Here is the wildwinds example: http://wildwinds.com/coins/ric/dioc...RIC_033a.jpg
BTW, welcome

























