Norms may also be understood as social realization of correctness notions and linguistic norms as performance instructions. This article reports on a case study of the application of Toury' s norm theory, particularly his operative translation norms, in subtitle translation. The authors believe that is a norm-governed communicative activity between two or more languages, and that subtitle translation, governed by linguistic and textual norms, should seek invisibility of subtitling as the ultimate goal.