NavList:

I agree. The terms and the distinctions themselves do not make much sense. The only one of these that I ever use with students, and that just to fill them in on the crappy terminology, is Hs. The others are confusing and worthless. There are many examples of peculiar terminology in celestial navigation, like "horizontal" parallax (is it sideways?), and "semi-diameter" (not radius?) and even "declination" (what's declining??). But these are historical terms that reflect the legacy of the development of navigation. They deserve a little respect, if only for historical "color". The acronym-happy late twentieth century has buried us in two-letter and three-letter shorthands that obscure rather than illuminate. Babbling about EP and AP and GP and all the rest isn't communication. This private, occult, semi-military jargon has become an unintentional barrier, a rite of passage with no educational purpose. I say, 'ditch it'. To which I should add a disclaimer: "IMNSHO". Ha!

Frank Reed