Russian
Russian pet name suffixes
Russian has two pet name suffixes, -eńka and -ečka (-знька, ‑зчка); -eńka is the more common form, Kóleńka, Fédeńka, etc., but if the syllable preceding the suffix in the basic word contains an n, -ečka is preferred: Sónečka, Ksénečka, etc. See Max Vasmer's short note, "Dissimilationsvermeidung im Russischen", Zeitschrift für vergleichenden Sprachforschung, vol. 51, Göttingen 1923.
He adds that a form like Mánečka also better expresses the purely hypocoristic function without the pejorative that could be attributed to a *Máneńka that sounds a little as Manka and the like.