The script is ogham, the early medieval writing system used across Ireland and parts of Britain in which letters are represented by notches and strokes cut along a central line, typically along the edge of a standing stone. This particular stone, roughly 1.1 metres long, bears its inscription on a flat face rather than an edge, which is already a little unusual. What makes it genuinely strange is what the inscription appears to say, and how it came to be carved at all.

The epigrapher R. A. S. Macalister, writing in 1945, read the inscription as UBEDABO ALTASI and concluded that it was the work of what he called an illiterate artificer, someone copying the letters by rote from a wooden template prepared to guide him, without any real understanding of the characters being reproduced. The result is an ogham inscription that may not communicate anything coherent at all, a kind of early medieval cargo-cult literacy in stone. The name ALTASI has drawn some interest in relation to the townland name Aultagh, though the connection remains speculative. Whether the stone was ever intended as a memorial, a boundary marker, or something else entirely, its garbled text makes it difficult to say with any confidence what purpose it was meant to serve.