Not long ago a clue cropped up in a crossword simply stating ‘Celtic language and writing system’. Now as somebody with a background in typesetting and in international marketing, I was confident of solving this particular conundrum.

Sadly I failed to conjure a direct answer, but by gaining a few contributory letters from fathoming contiguous clues I managed to complete enough of the word to make a dictionary reference. Up popped the answer of Ogham, a concept alien to me previously.

It transpires that Ogham is an alphabet and writing system for representing a number of mediaeval languages, instanced by Primitive Irish, Old Irish, Pictish, and Old Norse. Sometimes called the Celtic Tree Alphabet, Ogham had currency over the 4th to 10th centuries AD, principally in Ireland, Scotland, and Wales. Most inscriptions of the alphabet were rendered on perishable materials, such as wood. Research indicates that around 500 Ogham inscriptions survive on stone that served as territorial markers and memorials.

Some 25 letters constitute the alphabet (available as digital fonts) and are composed left to right in manuscripts and from bottom to top on sticks. Letters are linked together by a continuous line that echoes some Indian scripts. Over 400,000 references to Ogham are shown online. My crossword puzzle had revealed a formerly hidden academic discipline.

One wonders how many printers have set Ogham text?

Lawrence Wallis has held international pre-press marketing positions and is now a respected author and print historian.