UNLISTED OBVERSE LEGEND AND MINTMARK VARIETY. RIC lists for this type only longer obv. legend CONSTANTINVS MAX AVG [CONSTANTINOPLE 19 and CONSTANTINOPLE 26]. Shorter legend was in use earlier [CONSTANTINOPLE 7] so the present specimen might belong there. Also m.m. CONSis not attested. But note that such official issue probably does not exist. All known specimens should be regarded as ancient imitations or, mostly, as modern FORGERIES made by tooling rev. of common genuine coins.
There are also many forgeries of this type made by the same method (or by casting from genuine specimens) with listed (i.e. long) obv. legend. See also: Lars Ramskold, "Highly Deceptive Forgeries of Constantine’s SPES PVBLIC Coinage", The Celator, December 2009, pp. 18-32.
CONSTANTINOPLE [after 12], CONSTANTINE I, UNLISTED OBVERSE LEGEND [FORGERY]