This stamp for the Eucharistic bread is noteworthy because it is the earliest and the only known example of its kind in the middle Danubian region. Instead of the customary formula, the stamp bears (in the negative) a very unusual Greek inscription: ANTQIAC KACTAC. A free interpretation of this might be: "Be Antonians" or "Return to Antonius". This appeal for the return to the primitive Christian Church might have been addressed by St Atanasius, author of The Life of St Antonius, to Ursacius, the Arian bishop of Singidunumin 344. It was in that year that the great teacher of the Eastern Church came to the town and transferred the relics of the Singidunum martyrs to Aquileia, a classical town near Venice.
These martyrs were probably St Donatus and St Fortunatus, who had suffered martyrdom in Singidunum in Diocletian's first persecution of Christians in 303/4 A.D. By removing the relics of the patrons of the town, St Atanasius wanted to punish its inhabitants and censure its ecclesiastical dignitaries for apostasy. As a good teacher, however, he left a reminder of the path leading back to orthodoxy. That piece of instruction, seen in daily services in the impression on the Eucharistic bread, the body of Christ used in the Holy Communion, has been preserved on this bronze stamp to the present day.