[Tenoki]

A glottal stop is not really a normal letter (for example in German it is not written at all), while the H is more of one, and it is written with a “'” in Lojban.

Edit: The Lojban “'” can also be considered not to be a real phoneme but to be more like a gilde sound between two vowels.

But maybe the glottal stop is only in German not considered to be a phoneme. (Actually it is more of a short pause, the snap is only an easy but not necessary way to do it.)