The process of globalization, along with the advent of Internet technology, has resulted in the increasing presence of written mixed-language discourses produced and used by multilinguals in online spaces (e. g. online chat, instant messaging, and online discussion boards). Despite the fact that multilingual texts have become more visible and accessible, little research has empirically examined written mixed-language discourses and their sociopragmatic values (Sebba 2012). Drawing on ethnographic fieldwork on computer-mediated interaction among English-Korean bilinguals, this study explores how a certain multilingual practice became iconized as an ideological representation of authentic bilinguals and how such ideological constructs influenced their linguistic practices in written interaction. In particular, this study investigates how these bilinguals strategically create and use a non-standard variety of novel respelling forms in order to position themselves as "authentic" bilinguals and differentiate themselves from other potentially "inauthentic" and "failed" bilinguals. Findings suggest that multilingual texts and written mixed-language discourses need to be understood as an ideological site where different language ideologies and historical discourses are articulated, and where multilinguals try to authenticate themselves as legitimate bilinguals in a given discourse community.