Late Roman copper coins usually have mintmarks that abbreviate the name of the mint. Some are clear abbreviations such as "LVG" for LVGdunum (= modern Lyons). Some are not quite as clear, but decipherable, such as mintmark "PLG" for Pecunia LuGdunum (Money of Lugdunum). But there are some that are not so self-explanatory. 19 mm. 2.815 grams. CONSTANTINVS AVG Constantine, 307-337. Reverse legend: VICTORIAE LAET PRINC PERP Two victories holding shield inscribed VOT/PR on rectangular altar. Two captives seated back-to-back, in exergue. There are no letters abbreviating the name of the mint. We could probably identify the mint using finds and style, but the mint's next issue makes it easier. 18 mm. 3.10 grams. It has the same legends and design as the one above. This one has the mintmark P<two captives>L, which is just like the mintmark above but for the addition of P and L. Both coins are from Lugdunum. The first is RIC VII Lyons 65, page 126, struck "319-320" and the second RIC VII Lyons 79 page 128, struck "320". Show us coins with mintmarks that require some deciphering.