This paper presents an OT analysis of hypocoristic (nickname) formation based on previously unanalyzed data from Bernese Swiss German. The Bernese data are compared to the much discussed pattern of i-formation in Standard German, from which they differ in two important ways: the Bernese hypocoristics have Umlaut, and the syllable retained from the full name in the hypocoristic is not consistently the leftmost. The Umlaut phenomenon is shown to be an effect of the underlying shape of the hypocoristic suffix. The choice of syllable, while appearing to be a more marked pattern, can be shown to arise from the satisfaction of high-ranking, position-sensitive markedness constraints, illustrating the “emergence of the unmarked” in truncations.Earlier versions of this paper appeared in the McGill Working Papers in Linguistics (Grüter 2002) and were presented at the Montréal-Ottawa-Toronto (MOT) Phonology Workshop (McGill University, February 2002) and the Berkeley Germanic Linguistics Roundtable (UC Berkeley, April 2002). I am grateful to these audiences as well as to two anonymous JGL reviewers for helpful questions and comments. Special thanks are due to Heather Goad, whose extensive advice and encouragement have made this paper possible. All errors are of course my own. This research was supported by a McGill Major Fellowship.