When do mints get named on the coins? Well, Roman provincial mints are almost always clearly named on the reverse, but I am writing about imperial coins. Here is one of the first Roman imperial coin types to clearly indicate the mint: 22 mm. 4.10 grams. Aurelian, 270-275. His first issue at Serdica, dated to c. 271 by Estiot. SERD in exergue. IOVI STATORI, Jupiter standing left holding thunderbolt and long staff. IMP AVRELIANVS AVG. Estiot Monnaies de l'Empire Romain D'Aurélien à Florien (270-276 après J.-C.), page 389 listed in the conspectus but not numbered or plated. I think it must be rare or maybe very rare. The number would be near 994, plate 31 (with has the type without SERD) or 173 plate 81 (which has SERD, but with IOVI CONSERVATORI, a different type). ***** Here is an aside about that book with 2500 photographs. I find the arrangement of Estiot remarkably difficult to deal with. I've owned it for years and like coins of Aurelian and Tacitus, so you'd think I'd use it easily by now, but that is not the case. It has 100 large page plates of photos, usually with 24 life-sized coins per plate, so that's excellent photographic coverage. However, many types are given twice in two different places with two different coin numbers. Why would they do that? For example the Aurelian of Serdica on plate 31, number 992, is the same type as plate 81 with number 173. The plates have coins numbered 1 through 1998 and then they begin again with numbers 1 through 556 for the same coverage. Every number 1 through 315 is used twice for Aurelian for two different types. Why would they do that? I think someone decided to catalogue the large collection of the Bibliothèque Nationale with consecutive numbers 1 through 1998. Then they realized they needed a complete list and, separately, gave a conspectus of types. Those have their own images (if they could find images), beginning again from number 1. So any number has two different references in two different places. It could be easier on the user. ***** Enough of that. We know that the coin reform of Diocletian c. 294 produced large folles, most of which are clearly mintmarked with an abbreviation of the name of the mint. In August I posted a Numerian with LVG for Lugdunum (= Lyons). https://www.cointalk.com/threads/the-lugdunum-mint-challenge.347454/page-6#post-4782088 What other Roman imperial coins are from before the reform of Diocletian with mint names abbreviated in the mint marks?