Somebody wrote:

> > I though that h-digraphs were a relatively recent innovation in Irish
>> spelling

Not particularly. Some digraphs are found even in
very early materials, and always in Scottish

>I was referring to the phonetic significance; I wasn't suggesting
>that the usage came from Irish. (I think the Irish influence is the
>barring of d to form <ð> and a similar barring of b in Old Saxon.)

Neither of those occur in traditional Irish
orthography. It appears that the Saxons innovated
Michael Everson * * Everson Typography * *