VINDICATIO. - A term suggested by a text of St. Optatus of Milevis (De schismate Donatistarum, I, 16: PL 11, 917), by which it was intended to denote a kind of official recognition of martyrdom, according to the interpretation given by G. B. De Rossi to the abbreviation NP in the inscription of Pope Fabian, in which the abbreviation itself appears to have been added to the slab at a later time.
However, after the discovery of the epitaph of Pope Pontian, in which the same abbreviation was also added subsequently, it was thought that it could only signify the custom, in use from 258 onward, of inscribing upon the tombs of witnesses to the faith the honorary title of martyr, as is fully attested in the inscription of the martyr Hyacinthus, though the year of his martyrdom is unknown. Certainly, the use of affixing such an honorary title postdates the translation of the relics of Pope Cornelius, who died in exile in 253, since even on his slab the title martyr was added in full after his deposition in the cemetery of Callistus. The texts known regarding such a vindicatio all refer to the African Church, where bishops often had to vigilantly suppress abuses perpetrated by the Donatists.