Comments and/or corrections always welcome. Valens, AE3, Siscia. AD 364-367. DN VALEN-S PF AVG, pearl diademed, draped, cuirassed bust right. GLORIA RO-MANORVM, emperor walking right, holding labarum and dragging a captive behind him. Star over A in right field. Mintmark DBSISC. RIC IX Siscia 5b, type vii (a); Sear 19745. Rated common. Image rights: wildwinds.com Valens AE3 of Siscia. 364-367 AD. DN VALENS PF AVG, pearl-diademed, draped and cuirassed bust right. SECVRITAS REIPVBLICAE, Victory walking left, holding wreath and palm. No fieldmarks. Mintmark DASISC. RIC IX Siscia 7b, type iv; Sear 19831-19832.
If you're not sure you can count the letters or judge by the space the legend takes Valens has only 5 letters/spaces while Valentinian has 13.
My latest one : Valens Ae3 DN VALEN-S PF AVG / SECVRITAS REIPVBLICAE SMNB Nicomedia And you need some tricks for distinguishing between Valentinian Sr or Jr :https://www.cointalk.com/threads/valentinian-s-identification.352362/
For me, if you’re unsure between Valens and Valentinian just look at the size of the letters. Sort of like constans vs Constantius. Smaller letters mean a longer name or legend