When the antiquarian W.F. Wakeman first documented it in 1893, the inscription defeated him. The National Museum of Ireland, which eventually took custody of the stone, was similarly stumped for a time. It took until 1982, when Patrick Heraughty published his study of Inishmurray, for a convincing reading to emerge: a prayer, in mixed Irish and Latin, commemorating a man named Nerach, who made a cross called the Cross of Talt, offered up on behalf of communal souls.

The stone originally sat on the altar inside Teach Molaise, a small oratory within the cashel on Inishmurray Island, off the Sligo coast. A cashel, in this context, is a stone-walled monastic enclosure, and Inishmurray contains one of the most complete early medieval examples in Ireland. Teach Molaise, the house or church of Saint Molaise, sits within it. The inscription itself, carved into a thin flag measuring 31 centimetres tall and 21 centimetres wide, mixes Old Irish with Latin in a formula typical of early Christian memorial or dedicatory practice. The phrase "pro animis nostribus," for our souls, places it firmly within the tradition of prayers commissioned or carved in expectation of spiritual benefit. Heraughty's reading identifies Nerach as the maker of something called the Cross of Talt, though what that cross was, and whether it survived, is not recorded in the notes of the 1997 to 1999 archaeological survey carried out by Jerry O'Sullivan and Tomás Ó Carragáin, whose published volume remains the definitive account of the island's monuments.

The stone was removed from Inishmurray to the National Museum of Ireland in 1971, where it was registered under accession number 1971:1118. It is held in Dublin rather than on the island, which is uninhabited and accessible only by arranged boat from the Sligo coast. Anyone wishing to see the stone itself should contact the National Museum's collections in advance, as objects of this kind are not always on public display. The island, meanwhile, retains the altar and the cashel where the stone once rested, and the archaeological survey records the original location separately under its own monument number.