The medieval parish church of Seskinan at Knockboy, County Waterford, contains not one but seven ogham stones, and most of them have been quietly doing structural work for centuries. Ogham is an early medieval Irish script in which letters are encoded as groups of notches and lines cut along the edge of a stone, most often recording personal names. Six of the Seskinan stones have been pressed into service as lintels and building material, their inscriptions literally holding the place together. The seventh stone stands upright in a corner of the church, but it is a small fragment embedded in the arch above a south-wall window that carries a particular curiosity of its own.

That fragment, measuring roughly 36 by 5 centimetres, functions as a voussoir, one of the wedge-shaped stones that form the curve of an arch, slotted in above the window lintel. It was noticed there in 1851 by G. V. du Noyer, a geologist and antiquarian well known in nineteenth-century Irish fieldwork for his meticulous illustrations of ancient monuments. The inscription was later read by R. A. S. Macalister, whose 1945 corpus of Irish ogham stones remains a foundational reference, as simply CORB, a fragment of what was almost certainly a longer name or formula. How much the original stone said before it was cut down and built into the arch is impossible to know. The stone has since been examined as part of the Ogham in 3D project run by the School of Celtic Studies at the Dublin Institute for Advanced Studies, which uses digital scanning to record inscriptions that are sometimes too worn or awkwardly placed for the naked eye to resolve comfortably.