The medieval parish church of Seskinan at Knockboy, Co. Waterford, contains not one ogham stone but seven, and that number alone sets it apart. Six of them have been quietly pressed into service as lintels, the kind of repurposing that happened when early medieval inscribed stones were simply the most convenient large, flat material to hand. The seventh stands upright in a corner of the church, still vertical, as if it never quite accepted retirement. 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, and the Seskinan examples are among the more concentrated survivals of it anywhere in the country.

One of the lintel stones sits above the window at the eastern end of the north wall, and it was identified in 1851 by G. V. du Noyer, a draughtsman and geologist who made a significant contribution to recording Irish antiquities in the nineteenth century. The stone measures approximately 1.78 metres long and just over half a metre wide. Its inscription, chiselled along two angles and running up on one edge and down on another, faces inward toward the church interior rather than outward, meaning anyone who placed it there either did not know it was inscribed or did not consider the inscription the point any longer. The scholar R. A. S. Macalister, whose 1945 corpus of Irish ogham stones remains a foundational reference, read the surviving text as including the phrase MUCOI NETA-SEGAMONAS, a formula meaning something like "of the tribe of" or "descendant of" Neta-Segamon, a name that appears on several ogham stones and suggests a kin group active across parts of early medieval Munster.