Ogham is an early medieval script in which letters are represented by notches and strokes cut along the edge or face of a stone, and this particular example from Ballyknock carries its inscription along what scholars call the sinister angle, the left-hand edge of one of the broad faces. The stone itself is substantial, over six and a half feet tall and cut from clayslate, which gives it a flat, workable surface well suited to the script.

The group of fifteen stones had been repurposed, probably centuries after they were first inscribed, to serve as the lintels and side slabs of a souterrain, a type of underground stone-lined passage or chamber commonly associated with early medieval settlement in Ireland and often used for storage or refuge. Finding ogham stones reused in this way is not unusual; once a commemorative or boundary stone lost its immediate social function, it was practical building material. Scholars have puzzled over the name carved on this one. R. A. S. Macalister, reading it in 1945, rendered the inscription as COVALOTI. Damian McManus, returning to it in 2004, adjusted that slightly to C[O]VALUTi, the brackets indicating a letter he considered uncertain. The difference is small but reflects how much interpretation goes into reading stones that have spent centuries underground or exposed to the elements.

The stone is no longer at Ballyknock. It is held on permanent display in the Stone Corridor at University College Cork, a long vaulted passage that houses one of the largest collections of ogham stones in the world, many of them from County Cork and Kerry. The inscription is visible on the stone's edge, and knowing that scholars still disagree about one of its letters makes it worth looking at closely.