No huge deal, but it is fun to find a rare, unlisted in RIC variant. The common mint marks for Licinius in this series have dots, for example ·TSA· or ·TS·A· etc. TSA is found commonly on other types for Licinius and for other rulers (Crispus and Helena), but not on the IOVI series. Here is the one on NOTINRIC online... And here is another... NOTINRIC online conjectures that it could be an engravers error (just forgetting the dots), but as you can see, none of the three above coins are die-matched. So it's fair to consider the idea that the officina that was using the mark TSA (on other types and rulers) was briefly called into service to produce these. Perhaps they finished their quotas for the day early, and had nothing else to do?
Engraver's error or more likely, a filled die. I've seen many variations of the ·TS·A· mint mark with different combinations of the dots missing.
