Stan at Sentence first has a good post about the Hibernian use of “haitch” for the letter most of the English-speaking world knows as “aitch.” I’ve always found it charming, and am amused by the example he provides of an issue of “the local freesheet Galway Advertiser” that in repeating a headline on the second page of a story has “a HSE” (i.e., Haitch Ess Ee) where the first version had “an HSE” (i.e., Aitch Ess Ee; see his post for screenshots). I was even more amused by the misguided historical analysis underlying the peevery cited at the end of this passage:
The history of h-dropping and h-adding at the start of various words is quite a tangle, made worse by the fact that people often feel their own version must be correct and others’ therefore can’t be. I’ve seen real fury directed at the American practice of muting the H in herb, from listeners probably unaware that sounding the H was a later convention.
He goes on to discuss the history of the name “aitch,” which goes back (via Old French ache) to “a late Latin *accha, *ahha, or *aha,” and ends with the extremely interesting information that “haitch” is spreading—see the telling graph from John Wells—and the following speculation: “I wonder whether aitching H correlates at all with the wine–whine merger – or, phrased another way, whether haitching H correlates with pronouncing wine and whine differently.” Lots of good stuff in the comment thread as well.