"The secret language of the poets" and it's mastery was an important part of the teachings of the Druids. The Seers and Bards of both Wales and Ireland inscribed these letters on the edge of stones. Inscriptions of OGAM_(Ogham) have been found carved on standing stones throughout Britain, Scotland and Ireland from the fourth century CE onwards. It is assumed that they were grave markers. They were also used as boundry markers.

The letters are given mythological status in a number of early Irish texts.