The investigation in this paper is based on the Swiss SMS corpus. In a first step, the use of the two varieties Swiss German Dialects and Standard Swiss German are investigated as to who uses which variety and why informants decide to switch varieties. In a second part, the focus is on the spelling of the Swiss German dialects, a group of varieties without spelling norms. This lack of norms leads to an abundance of different spelling forms for the same signifié and accordingly to restrictions when working with the corpus. An additional layer of equivalent terms in Standard German will be created in the corpus to assist researchers.