I have been waiting patiently for one of these for a long time too. No luck yet. Congratulations on yours. It is a nice example.
I think the
legend must refer to Diocletian's entire reform and not this
denomination, which as
Peter notes is far to
rare to be useful. I suspect it may have been issued right at the beginning of the reform. Maybe even for gifting to the public.
But Peter's point stands. I have always thought that the reform itself must have been rather inconvenient. Though there is
still not total agreement on the values of the
new coins, most people acknowledge that the main
denomination was much higher than the previous Aurelianus (
aka Aurelianianus / late
Antoninianus) while the new
radiate was of similar value but not as common.
Thus the new reform would appear to have left a shortage of small change. A token issue of
denarii communes would not have helped. Hence the old, small
Antoniniani appear to have remained in circulation.
Shawn