apostrophes in transliteration

I'm starting a list of things I've seen apostrophes used for in
transliteration systems, natlang, conlang or otherwiselang:

1.  morpheme boundaries, especially (it seems?) in agglutinating-type
languages
2.  glottal stops
3.  aspiration (it's used this way in McCune-Reischauer with respect to
Korean)
4.  contractions (like "can't" in English, though I suppose that's
strictly speaking not a transliteration)
5.  unfortunately, people in pulp sf/f who use names like Xe'tar'tika and
insert apostrophes indiscriminately to make things like "exotic"

Anyone know of any others?  :-p

YHL the whimsical