It is one of two ogham stones, those early medieval Irish monuments inscribed in the linear alphabet of notched strokes cut along a stone's edge, that came to light around 1840 when a flour mill was demolished near Mountrivers in County Cork. The mill, it turns out, had been built on the site of a possible ringfort, one of the circular enclosed farmsteads that once dotted the Irish countryside in their thousands, and the stones had apparently been absorbed into its fabric without ceremony.

The stone was broken before the Royal Cork Institution acquired it, and the fracture is more than cosmetic. Inscribed on two sides, it would originally have carried a continuous text running across a linking section that is now missing entirely. What survives of the inscription was read by the scholar R. A. S. Macalister, who devoted much of his career to cataloguing Ireland's ogham corpus, as MAQI-BRI..... CELI ALACA, a partial formula typical of early medieval memorial stones that would once have named a person and their lineage. The gaps where letters have been lost make a full interpretation impossible. Adding to the puzzle, the 1842 Ordnance Survey Name Books recorded a third ogham stone connected with this find spot, though the researcher P. J. Hartnett argued in 1939 that this supposed third stone was most likely the missing fragment of the broken one, not a separate monument at all. Whether that fragment survives anywhere is unknown.