Ogham is an early medieval script in which letters are formed by notches and lines cut along the edge of a stone, typically used to commemorate the dead, and its appearance here alongside what is essentially a Christian devotional site suggests a long and layered history of use. The stone on the north-west side of the cairn is upright, roughly a metre tall and noticeably narrow, with its inscription cut along one of its edges in the characteristic manner of the script.

The scholar R. A. S. Macalister, writing in 1945, read the surviving inscription as LACAVAGNI, a name in the genitive case of the sort commonly found on Irish ogham stones, meaning roughly "of Lacavagnus" or belonging to a person of that name. What makes his reading particularly poignant is the qualification he adds: above that single word, for a span of just over a foot and a half, the angle of the stone has been entirely chipped away, taking whatever else was once inscribed there with it. Whether that damage is ancient or more recent, deliberate or accidental, is not recorded. What survives is a fragment of a name, the remainder lost to erosion or interference, preserved just well enough to be tantalising.