One of my langs has apostrophes in transliterations to mark out prefixes; I've also used hyphens for this purpose, and I generally go back and forth with my preference. This use is less justified, because it doesn't reflect either the pronunciation or the lang's native writing system (which has a superstitious rule that *any* break or silence must be marked but doesn't use markings for word extention), but it helps me remember where the different word parts end and begin.