This paper, which seeks to contribute to the field of Interactional Onomastics (De Stefani 2016), addresses onymic forms of self-reference in computer-mediated interactions. Applying theoretical and methodological concepts developed in Conversation Analysis and Interactional Linguistics, the study looks at onymic forms as communicative practices. In SMS and Whats- App exchanges, participants systematically deviate from the default use of the deictic pronoun and shifter ich (I) and mobilize a range of different onymic forms (e.g. personal names, kinship terms, pet names, ad hoc titles, categorizations etc.) as communicative practices when referring to themselves. I argue that these onymic forms, which go against the „preference for using a minimal form“ (Sacks/Schegloff 1979), do more than simply refer to the speaker/ writer: Participants use address inversions and third person reference forms (instead of the deictic pronoun ich) as „social indices“ (Silverstein 1976: 37) to contextualize various social meanings – which would be hidden in cases of „referring simpliciter“ (Schegloff 1996) – by means of the deictic pronoun ich.