Continuing from yesterday’s entry, morphologically fickle vowels in Kharulian are called ich [itʃ] (singular ílyit [ˈi.lʲət]), which means “gaps” or “openings”. The second i in ílyit is an example, since it disappears in all the oblique forms: accusative icho [ˈi.tʃo], genitive ichi [ˈi.tʃi], etc. In this case, the fact that the l also disappears in the oblique forms (and palatalizes the t) obscures the pattern somewhat.
A more straightforward example is my Lexember 16 entry, lyóbor [lʲo.bɔr]; the second o is an ílyit, and the oblique forms all use the stem lyopr-.