here. He studied more than 100 examples, went back to the original source used by the authors of RIC, and corrected RIC (and not just for #607). I summarize these corrections here: Moreover, he catalogs all of the examples he studied and breaks them down by officina markings, inscription breaks on the reverse, and bust types. He also proposes an issue he attributes to the Siscia mint. Interesting stuff. Using his paper and his corrections to RIC, we can attribute this coin from my collection thus: Maximian, AD 286-308 Roman billon pre-reform antoninianus; 3.78 g, 23.0 mm Obv: IMP C M A MAXIMIANVS AVG, radiate, draped and cuirassed bust, right Rev: CONCORDIA MILITVM•, Emperor standing r., receiving Victory from Jupiter standing l., Γ below; in exergue: XXI• So, we see this is RIC 607 after noting the corrections. Consulting Table 1 in Roll-Vélez ... and noting OL2 reads "IMP C M A MAXIMIANVS AVG" We can identify this coin as Roll-Vélez 9 But as detailed as Roll-Vélez's article is, it doesn't list a coin of this officina with a reverse inscription with a dot after MILITVM. So clearly, there is more study to be done on this facinating issue. I have sent a photo of my coin and my observations to Prof. Roll-Vélez. I'll let you guys know what he has to say about it.